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So I have heard/had a couple debates about this and what it means.

When a rule refers to "Units in this formation do X" how does this affect ICs and dedicated transports?

The Codex: CW book talks about the Aspect host adding 1 to BS or WS immediately after determing warlord traits. I have read it argued here that wave serpent Dedicated Transports would gain the +1 BS. Is a DT that is purchased with a unit from a formation part of that formation (detachment)?

The Codex: Tempestus Scions airborne formation gives bonuses when a "unit from this formation" disembarks with grav chutes. If an IC (say a GK Brother-Captain) joins a unit from the formation and "becomes part of the unit for all rules purposes" will it now gain the benefits of the formation if it grav chutes in with the unit?

Finally, for example, the formation requires a "commissar" from Tempestus Scions. While in the AM book a Lord Commissar is a different unit entirely than a Commissar (different rules for purchase) in the TS book it is an upgraded Commissar. Is a "Lord Commissar" just an upgraded commissar and then valid for the airborne formation? The more I have been looking at this the more I am starting to lean toward "no" since the Grey Knight uber-formation requires both a Brother-Captain and a Chapter Master and the Chapter-Master is an upgraded brother-captain. Thoughts on these?

Lendys wrote:
When a rule refers to "Units in this formation do X" how does this affect ICs and dedicated transports?

If they are an IC or Transport bought with the formation, then they benefit from the rule. If not then they do not.

Was this a serious question?

 DeathReaper wrote:

Lendys wrote:
When a rule refers to "Units in this formation do X" how does this affect ICs and dedicated transports?

If they are an IC or Transport bought with the formation, then they benefit from the rule. If not then they do not.

Was this a serious question?

It was, because some of the rules get a little odd, especially with transports gaining their own battlefield roles if they are purchased separately. For example. the Eldar Aspect host. You purchase 3 units of fire dragons and purchase 3 Wave Serpents to go with them. The Wave serpents are separate units from the fire dragons, they "do not take up a force organization slot." The Formations sidebard on 121 states: "the Army List Entries that comprise a formation are listen on it, along with any special rules that those units gain." The Army list entry for the Aspect Host lists out a bunch of aspects but leaves out wave serpents. Wave serpents are an "Army List Entry" so it seems that they are, in fact, not part of the formation since a dedicated transport is not the same unit as the unit that purchased said transport. This raises the question as to where the heck the wave serpents would go detachment wise and whether they would benefit from the +1 BS that could be selected for the aspect host.

For the IC question. The Tempestus Scion Airborne formation says "on any turn in which a unit from this formation disembarks...it has the Split Fire special rule, and all of its ranged weapons have Twin-linked special rule." Here's where it starts getting weird. If I have an IC join one of my units of scions in the formation "he counts as part of the unit for all rules purposes, though he still follows the rules for characters." A little later it says "unless specified in the rule itself, the unit's special rules are not conferred upon IC, [and vice versa.] Special rules that are conferred to the unit only apply for as long as the IC is with them." It seems that maybe the second sentence is modifying only those rules that specifically say they are conferred (i.e. stealth.)

Another rule of the Airborne formation lets "units form the formation re-roll the scatter dice" when they are using grav-chute insertion special rule. Does this rule affect the IC from outside the formation in this case? He's part of the unit "for all rules purposes."

I guess this is my view...If the Eldar Aspect Host benefit would confer to the Wave Serpent Transports (which are different units vaguely attached to the aspects that are in the formation) then the IC would get the special rule for "units from this formation" as long as he is with a unit from that formation since he is part of the unit "for all rules purposes" If the IC doesn't get those rules, then the wave serpents wouldn't either. Of course, this also opens up the question of if you can purchase wave serpents at all for your aspects, and if you can, what detachment they are a part of because they are not in the army list entries as part of the formation.

If the unit is not a part of a particular formation, then they are not a part of that formation...



Automatically Appended Next Post:

Lendys wrote:
Another rule of the Airborne formation lets "units form the formation re-roll the scatter dice" when they are using grav-chute insertion special rule. Does this rule affect the IC from outside the formation in this case? He's part of the unit "for all rules purposes."

But he isn't

If he were "part of the unit "for all rules purposes."" then the IC would not count for VP's if he is individually destroyed...

 DeathReaper wrote:
If the unit is not a part of a particular formation, then they are not a part of that formation...



Automatically Appended Next Post:

Lendys wrote:
Another rule of the Airborne formation lets "units form the formation re-roll the scatter dice" when they are using grav-chute insertion special rule. Does this rule affect the IC from outside the formation in this case? He's part of the unit "for all rules purposes."

But he isn't

If he were "part of the unit "for all rules purposes."" then the IC would not count for VP's if he is individually destroyed...

Then would you contend that Wave Serpents purchased by aspects in an Aspect Host are not part of the formation, cannot benefit from the formation benefit, and therefore form their own detachment of random elite wave serpents but remain DTs for the fire dragons that purchased them.

If the Wave Serpent was bought as a part of the detachment, then it is a part of the detachment...

 DeathReaper wrote:
But he isn't

If he were "part of the unit "for all rules purposes."" then the IC would not count for VP's if he is individually destroyed...

He counts as a vp because the rules specify that he does.

He becomes part of the unit joined for all rules purposes.

However there is the caveat that he does not gain a units special rules(although he can benefit from certain special rules, depending on wording of those rules).

A DT bought for a specified unit in a formation is a part of that formation and gains the formation benefits.

An ic that joins a unit becomes a part of that unit(thus negating pe if the unit is not a pe and the ic is), but gains no special rules possessed by that unit(i.e. firmation benefits)

 Kommissar Kel wrote:

 DeathReaper wrote:
But he isn't

If he were "part of the unit "for all rules purposes."" then the IC would not count for VP's if he is individually destroyed...

He counts as a vp because the rules specify that he does.

He becomes part of the unit joined for all rules purposes.

I know "He counts as a vp because the rules specify that he does."

I was just illustrating how the "for all rules purposes." is not actually "for all rules purposes."

However that is a little off topic.

Bottom line is:

If a unit is not bought for a particular formation, then they are not a part of that formation.

Generally, if a Detachment or Formation benefit says "Unit in this formation get...", then attached ICs benefit as the overall unit gains the benefit. If instead, it says "Models from this formation get...", then attached ICs don't.

It really depends on the individual rules and how it's written.

 Kriswall wrote:
Generally, if a Detachment or Formation benefit says "Unit in this formation get...", then attached ICs benefit as the overall unit gains the benefit. If instead, it says "Models from this formation get...", then attached ICs don't.

It really depends on the individual rules and how it's written.

This

As far as transports go. It is a separate unit that is not listed in the formation unit list. So i don't believe it counts as a unit in the formation

 jokerkd wrote:

 Kriswall wrote:
Generally, if a Detachment or Formation benefit says "Unit in this formation get...", then attached ICs benefit as the overall unit gains the benefit. If instead, it says "Models from this formation get...", then attached ICs don't.

It really depends on the individual rules and how it's written.

This

As far as transports go. It is a separate unit that is not listed in the formation unit list. So i don't believe it counts as a unit in the formation

In a Battle-Forged army, all models must belong to a detachment. Dedicated Transports belong to the Detachment (or Formation) they were selected for. Dedicated Transports selected for a required unit in a Formation absolutely are considered part of that Formation. If they aren't, what Detachment/Formation would you consider them a part of?

Thats where i hit the brick wall. It has been argued that because it does not take up a slot, it doesn't have to have a detachment. While i dont agree with that, i struggle to reconcile the fact that it must be in a detachment, but is a unit that is not listed in the formation units list. Thats where i see a conflict

 jokerkd wrote:
Thats where i hit the brick wall. It has been argued that because it does not take up a slot, it doesn't have to have a detachment. While i dont agree with that, i struggle to reconcile the fact that it must be in a detachment, but is a unit that is not listed in the formation units list. Thats where i see a conflict

Surely there is no conflict?

A made up formation;

2 tactical squads

benefits relentless.

If i purchase a DT those are units in their own right, they must belong to the same detachment as the unit they were purchased for, this formation doesn't say 2 Tactical squads and 2 rhinos, I've broken the formation requirements no?

If it says, each tactical squad may purchase a DT then I've not broken the restrictions.

** EDIT**

Although a quick bit of reffering to the many formations littered around my room shows the restrictions are all very differently worded. Some specifically allow DT some Prohibit them and other dont mention them...

Lendys wrote:
So I have heard/had a couple debates about this and what it means.
When a rule refers to "Units in this formation do X" how does this affect ICs and dedicated transports?
The Codex: CW book talks about the Aspect host adding 1 to BS or WS immediately after determing warlord traits. I have read it argued here that wave serpent Dedicated Transports would gain the +1 BS. Is a DT that is purchased with a unit from a formation part of that formation (detachment)?

Dedicated transports options are a bit of an issue for formations. Its generally accepted that if the unit in the formation has the option to purchase a transport it may, and that transport will also be part of the formation. Trouble is this is a widely accepted house rule. The BRB does nothing to address the issue at all so there is no RAW to fall back on but as I mentioned the 40k community seems to agreed how this should be played.

Lendys wrote:
The Codex: Tempestus Scions airborne formation gives bonuses when a "unit from this formation" disembarks with grav chutes. If an IC (say a GK Brother-Captain) joins a unit from the formation and "becomes part of the unit for all rules purposes" will it now gain the benefits of the formation if it grav chutes in with the unit?

If we take a very simplied look at it we could go with this example. Units are like rooms, detachments/formations are buildings, your army is a city and models are people. John and Bob and Steve are scion models. They are the only models left in the unit so John, Bob and Steven are standing alone in room 301 of the MT building. Harry, a brother captain, decides to join them. He leaves his room 101 in the GK building next door to the MT building and enters room 301 of the MT building. Just being in one of the rooms in the MT building is all Harry needs to get the benefits the MT building provides.

Lendys wrote:
Finally, for example, the formation requires a "commissar" from Tempestus Scions. While in the AM book a Lord Commissar is a different unit entirely than a Commissar (different rules for purchase) in the TS book it is an upgraded Commissar. Is a "Lord Commissar" just an upgraded commissar and then valid for the airborne formation? The more I have been looking at this the more I am starting to lean toward "no" since the Grey Knight uber-formation requires both a Brother-Captain and a Chapter Master and the Chapter-Master is an upgraded brother-captain. Thoughts on these?

The difference here is that the requirement of including a GK grand master can only be filled by buying a brother captain and upgrading him. In the MT formation there is no restriction that says you can't upgrade the required commissar to a lord commissar.

 DJGietzen wrote:

Lendys wrote:
So I have heard/had a couple debates about this and what it means.
When a rule refers to "Units in this formation do X" how does this affect ICs and dedicated transports?
The Codex: CW book talks about the Aspect host adding 1 to BS or WS immediately after determing warlord traits. I have read it argued here that wave serpent Dedicated Transports would gain the +1 BS. Is a DT that is purchased with a unit from a formation part of that formation (detachment)?

Dedicated transports options are a bit of an issue for formations. Its generally accepted that if the unit in the formation has the option to purchase a transport it may, and that transport will also be part of the formation. Trouble is this is a widely accepted house rule. The BRB does nothing to address the issue at all so there is no RAW to fall back on but as I mentioned the 40k community seems to agreed how this should be played.

Actually in the FOC Charts and Slots section:
"Army List Entries That Do Not Use Force Organisation Slots
Occasionally a unit’s Army List Entry will state that the unit it describes does not take up a slot on a Force Organisation Chart. These units can be included in any Detachment, even if all the slots of the appropriate Battlefield Role are filled with other units or if the Detachment had no slot for their Battlefield Role, but they must still adhere to any restrictions detailed on the Detachment and its own Army List Entry. If the Army List Entry states that it can be included in an army that includes another specified unit, and that it does not take up a Force Organisation slot, it must join the same Detachment as that specified unit. In either case, these units are part of the Detachment for all rules purposes and will gain any appropriate Command Benefits."

So it is in the rulebook for DTs to be part of the Detachment with the unit that purchased it. Formations are not excluded from this rule.

Yeah, ive read that passage before. Its not relavent to the DT question. 1st it does nothing to awnser the question if an included unit in a formation can take a dedicated transpirt not specifically included in the formation. 2nd none of the dedicated transports army list entries state they maybe included in an army that contains another specified unit.

 DJGietzen wrote:
Yeah, ive read that passage before. Its not relavent to the DT question. 1st it does nothing to awnser the question if an included unit in a formation can take a dedicated transpirt not specifically included in the formation. 2nd none of the dedicated transports army list entries state they maybe included in an army that contains another specified unit.

Actually, it's quite relevant. Unless specified in the Restrictions of the detachment/formation, units may be purchase options as normal. Formation general rules do not state that Dedicated Transports may not be taken for units which qualify. In other words, don't go looking for special permission when general permission is not denied.

The second is not even a valid point. There are numerous codices right now with no Dedicated Transport Role in them. For a model to actually BE a Dedicated Transport (and not just in the Dedicated Transport Role like the IG Chimera) , it must first be purchased by another unit. The rules on Dedicated Transports actually delineate this quite well. The first part is in Transports, and the other part is near the part I quoted above. The part I quoted above handles the rest.

DeathReaper wrote:

Lendys wrote:
When a rule refers to "Units in this formation do X" how does this affect ICs and dedicated transports?

If they are an IC or Transport bought with the formation, then they benefit from the rule. If not then they do not.

Was this a serious question?

Don't be rude. This is a very complicated game system, and while I am relatively good with it, I still trip up on stuff. I've played six editions of this game, and after that, coupled with limited time to play, sometimes even seemingly simple things can appear difficult.

Charistoph wrote:

 DJGietzen wrote:

Lendys wrote:
So I have heard/had a couple debates about this and what it means.
When a rule refers to "Units in this formation do X" how does this affect ICs and dedicated transports?
The Codex: CW book talks about the Aspect host adding 1 to BS or WS immediately after determing warlord traits. I have read it argued here that wave serpent Dedicated Transports would gain the +1 BS. Is a DT that is purchased with a unit from a formation part of that formation (detachment)?

Dedicated transports options are a bit of an issue for formations. Its generally accepted that if the unit in the formation has the option to purchase a transport it may, and that transport will also be part of the formation. Trouble is this is a widely accepted house rule. The BRB does nothing to address the issue at all so there is no RAW to fall back on but as I mentioned the 40k community seems to agreed how this should be played.

Actually in the FOC Charts and Slots section:
"Army List Entries That Do Not Use Force Organisation Slots
Occasionally a unit’s Army List Entry will state that the unit it describes does not take up a slot on a Force Organisation Chart. These units can be included in any Detachment, even if all the slots of the appropriate Battlefield Role are filled with other units or if the Detachment had no slot for their Battlefield Role, but they must still adhere to any restrictions detailed on the Detachment and its own Army List Entry. If the Army List Entry states that it can be included in an army that includes another specified unit, and that it does not take up a Force Organisation slot, it must join the same Detachment as that specified unit. In either case, these units are part of the Detachment for all rules purposes and will gain any appropriate Command Benefits."

So it is in the rulebook for DTs to be part of the Detachment with the unit that purchased it. Formations are not excluded from this rule.

Thanks for sourcing this paragraph, it clears things up for me pretty well.

Charistoph wrote:

 DJGietzen wrote:
Yeah, ive read that passage before. Its not relavent to the DT question. 1st it does nothing to awnser the question if an included unit in a formation can take a dedicated transpirt not specifically included in the formation. 2nd none of the dedicated transports army list entries state they maybe included in an army that contains another specified unit.

Actually, it's quite relevant. Unless specified in the Restrictions of the detachment/formation, units may be purchase options as normal. Formation general rules do not state that Dedicated Transports may not be taken for units which qualify. In other words, don't go looking for special permission when general permission is not denied.

The second is not even a valid point. There are numerous codices right now with no Dedicated Transport Role in them. For a model to actually BE a Dedicated Transport (and not just in the Dedicated Transport Role like the IG Chimera) , it must first be purchased by another unit. The rules on Dedicated Transports actually delineate this quite well. The first part is in Transports, and the other part is near the part I quoted above. The part I quoted above handles the rest.

So we have two lines in the, as I will continue to refer to it, irrelevant passage. The 1st. "Occasionally a unit’s Army List Entry will state that the unit it describes does not take up a slot on a Force Organisation Chart. These units can be included in any Detachment, even if all the slots of the appropriate Battlefield Role are filled with other units or if the Detachment had no slot for their Battlefield Role, but they must still adhere to any restrictions detailed on the Detachment and its own Army List Entry." This can't apply to dedicated transports because it says " a unit’s Army List Entry will state that the unit it describes does not take up a slot " and not a single dedicated transport army list entry says that. There is a separate rule dealing with dedicated transports and slots and it does not alter the army list entry. Lets pretend it did for just a second. It would only mean "these units can be included in any Detachment, even if all the slots of the appropriate Battlefield Role are filled with other units or if the Detachment had no slot for their Battlefield Role" and while that gives them permission to be in the same detachment, it does not require it.
The second part, "If the Army List Entry states that it can be included in an army that includes another specified unit, and that it does not take up a Force Organisation slot, it must join the same Detachment as that specified unit. In either case, these units are part of the Detachment for all rules purposes and will gain any appropriate Command Benefits." requires that the units army list entry state "that it can be included in an army that includes another specified unit". Again, not even remotely mentioned. The units option to take a dedicated transport does not add this line to an army list entry.
Finally 7th edition codices don't even have army list entries for dedicated transports. How could any of this apply to army list entries that don't exist?

The rules for adding a dedicated transport to your army are not the same as adding a unit with an army list entry that states it's unit does not take up a slot. This passage is only relevant to the latter.

 DJGietzen wrote:
So we have two lines in the, as I will continue to refer to it, irrelevant passage. The 1st. "Occasionally a unit’s Army List Entry will state that the unit it describes does not take up a slot on a Force Organisation Chart. These units can be included in any Detachment, even if all the slots of the appropriate Battlefield Role are filled with other units or if the Detachment had no slot for their Battlefield Role, but they must still adhere to any restrictions detailed on the Detachment and its own Army List Entry." This can't apply to dedicated transports because it says " a unit’s Army List Entry will state that the unit it describes does not take up a slot " and not a single dedicated transport army list entry says that. There is a separate rule dealing with dedicated transports and slots and it does not alter the army list entry. Lets pretend it did for just a second. It would only mean "these units can be included in any Detachment, even if all the slots of the appropriate Battlefield Role are filled with other units or if the Detachment had no slot for their Battlefield Role" and while that gives them permission to be in the same detachment, it does not require it.

So, I guess that you didn't actually read the sections on Dedicated Transports I referenced otherwise you would either not still consider the section useless.

From the Transports > Dedicated Transports and Choosing Your Army > Force Organization Charts and Slots > Dedicated Transports:
"Sometimes a unit entry will include a transport option, allowing a vehicle to be selected together with the unit. These Dedicated Transports do not use up a slot on the force organisation chart, but count as having the same role as the unit they were bought for all other rules purposes."

So any unit that has a Dedicated Transport purchased with it, will have that Transport be included in the same detachment per the previously "irrelevant passage".

 DJGietzen wrote:
The second part, "If the Army List Entry states that it can be included in an army that includes another specified unit, and that it does not take up a Force Organisation slot, it must join the same Detachment as that specified unit. In either case, these units are part of the Detachment for all rules purposes and will gain any appropriate Command Benefits." requires that the units army list entry state "that it can be included in an army that includes another specified unit". Again, not even remotely mentioned. The units option to take a dedicated transport does not add this line to an army list entry.
Finally 7th edition codices don't even have army list entries for dedicated transports. How could any of this apply to army list entries that don't exist?

You are confusing two different concepts.

First off, there are units in the Dedicated Transport ROLE. These are the units listed under the Dedicated Transport section of the army list. This is a Role that is disappearing as more codices come out after 7th Edition and army lists are replaced with datasheets.

Now, secondly, there are units that can be purchased as Dedicated Transports. Some are listed in the Dedicated Transport Role, some are listed under other Roles. For an example, Codex Marine Terminators are allowed to purchase a Land Raider, Land Raider Crusader, or Land Raider Redeemer as a Dedicated Transport. Per the codex army list entry, "The unit may select a Land Raider of any type as a Dedicated Transport (pg 177)." Now the Land Raider types are under the Heavy Support Role, not Dedicated Transport like the Rhino. Yet, those Terminators are still able to have Land Raiders as Dedicated Transports. Just like Praetorians can for Night Scythes and Eldar Guardians can take a Wave Serpent.

 DJGietzen wrote:
The rules for adding a dedicated transport to your army are not the same as adding a unit with an army list entry that states it's unit does not take up a slot. This passage is only relevant to the latter.

Actually, they are. Read the Dedicated Transport sections again. Read the unit datasheets and army list entries and what they say.

From a rules perspective, I understand the arguments on both sides of this one, but it's very wonky for me.

I think the biggest argument against including Dedicated Transports as receiving Formation bonuses is if they are not LISTED in the Formation.

The Dire Avenger Shrine simply lists 3 units of Dire Avengers. That is the formation. It does not mention Wave Serpents anywhere.

Thus my reasoning would be that Dire Avengers taken as part of the formation may purchase a Wave Serpent as normal. The Wave Serpent counts as a Troops choice per the rules for Dedicated Transports, and the Wave Serpent counts as being part of the same Detachment/Formation as the Dire Avengers (ie the Dire Avenger Shrine). But because the Formation itself explicitly says that it consists of 3 Units of Dire Avengers, then I don't think they receive any of the bonuses.

The Dedicated Transports act just like normal Dedicated Transports. They basically tag along with whatever unit brings them, but they don't use up a slot. So they're part of the Dire Avenger Shrine, but not really.

I feel like if the spirit of the rule was for Wave Serpents to benefit in this way, the phrasing of the rules themselves would say "Dire Avengers and Dedicated Transports in this formation may... etc".

So here's an amusing question for you.

If you take an Aspect Shrine with three units of Striking Scorpions, and choose to increase their WS by 1, do all the Wave Serpents in the formation now count as being WS2?

Murrdox wrote:
So here's an amusing question for you.

If you take an Aspect Shrine with three units of Striking Scorpions, and choose to increase their WS by 1, do all the Wave Serpents in the formation now count as being WS2?

No, because Serpents do not have a WS. And when they do, it is a set modifier so would apply after the +1.

The way I see it is formations are a type of detachment as the rules say. A dedicated transport is part of a detachment but doesn't take up any slots or have anywhere to actually go in the foc. Dedicated transports are effectively an upgrade/piece of equipment for a unit, but act as a separate unit. Saying that this upgrade/equipment for a squad isn't part of the formation is similar to saying buying extra dire avengers don't qualify as part of the formation because the formation doesn't say anything about being allowed to buy other upgrades and equipment

 HANZERtank wrote:
The way I see it is formations are a type of detachment as the rules say. A dedicated transport is part of a detachment but doesn't take up any slots or have anywhere to actually go in the foc. Dedicated transports are effectively an upgrade/piece of equipment for a unit, but act as a separate unit. Saying that this upgrade/equipment for a squad isn't part of the formation is similar to saying buying extra dire avengers don't qualify as part of the formation because the formation doesn't say anything about being allowed to buy other upgrades and equipment

Eh even then I wouldn't agree with this interpretation. Dedicated Transports still count as their own unit, they grant kill points if they're destroyed, etc. It'd be too big a leap to treat them as war gear. During gameplay the wave serpent and the dire avengers are completely separate units on the table.

What you're talking about is more relevant to an argument for example with Tau Shield drones purchased by a Riptide.

Murrdox wrote:

Eh even then I wouldn't agree with this interpretation. Dedicated Transports still count as their own unit, they grant kill points if they're destroyed, etc. It'd be too big a leap to treat them as war gear. During gameplay the wave serpent and the dire avengers are completely separate units on the table.

So? What does that have to do with it? The rules covering that have already been quoted. Why ignore them?

Murrdox wrote:
What you're talking about is more relevant to an argument for example with Tau Shield drones purchased by a Riptide.

Not really. Tau Shield Drones are closer to the Exarchs and Sword Brethren, true. But they are still purchased in the same manner, as an option for the unit. The fact that they are granted extra rules by how they were purchased is the only real difference.

Heck, would you feel the same about Imperial Guard Platoons? Those things start out as 3 separate units! Never mind how many units it can make fully fleshed out before Dedicated Transports!

 DJGietzen wrote:

Charistoph wrote:

 DJGietzen wrote:
Yeah, ive read that passage before. Its not relavent to the DT question. 1st it does nothing to awnser the question if an included unit in a formation can take a dedicated transpirt not specifically included in the formation. 2nd none of the dedicated transports army list entries state they maybe included in an army that contains another specified unit.

Actually, it's quite relevant. Unless specified in the Restrictions of the detachment/formation, units may be purchase options as normal. Formation general rules do not state that Dedicated Transports may not be taken for units which qualify. In other words, don't go looking for special permission when general permission is not denied.

The second is not even a valid point. There are numerous codices right now with no Dedicated Transport Role in them. For a model to actually BE a Dedicated Transport (and not just in the Dedicated Transport Role like the IG Chimera) , it must first be purchased by another unit. The rules on Dedicated Transports actually delineate this quite well. The first part is in Transports, and the other part is near the part I quoted above. The part I quoted above handles the rest.

So we have two lines in the, as I will continue to refer to it, irrelevant passage. The 1st. "Occasionally a unit’s Army List Entry will state that the unit it describes does not take up a slot on a Force Organisation Chart. These units can be included in any Detachment, even if all the slots of the appropriate Battlefield Role are filled with other units or if the Detachment had no slot for their Battlefield Role, but they must still adhere to any restrictions detailed on the Detachment and its own Army List Entry." This can't apply to dedicated transports because it says " a unit’s Army List Entry will state that the unit it describes does not take up a slot " and not a single dedicated transport army list entry says that. There is a separate rule dealing with dedicated transports and slots and it does not alter the army list entry. Lets pretend it did for just a second. It would only mean "these units can be included in any Detachment, even if all the slots of the appropriate Battlefield Role are filled with other units or if the Detachment had no slot for their Battlefield Role" and while that gives them permission to be in the same detachment, it does not require it.
The second part, "If the Army List Entry states that it can be included in an army that includes another specified unit, and that it does not take up a Force Organisation slot, it must join the same Detachment as that specified unit. In either case, these units are part of the Detachment for all rules purposes and will gain any appropriate Command Benefits." requires that the units army list entry state "that it can be included in an army that includes another specified unit". Again, not even remotely mentioned. The units option to take a dedicated transport does not add this line to an army list entry.
Finally 7th edition codices don't even have army list entries for dedicated transports. How could any of this apply to army list entries that don't exist?

The rules for adding a dedicated transport to your army are not the same as adding a unit with an army list entry that states it's unit does not take up a slot. This passage is only relevant to the latter.

You don't see how it clearly states you it can be part of any detachment you want? They are part of the formation because they are purchased by the formation as a legal upgrade. There is absolutely no reason not to consider them part of the detachment it is a logical leap. Otherwise they have no detachment. Or are decicated transports now their own formation

Dedicated transports are akin to AM heavy weapon squads in a platoon.

In a formation that uses platoons as the basis of the formation you can freely take heavy weapons squads, special weapons squads, platoon command squads, 2-5 platoon infantry squads, and/or conscripts(along with chimeras and/or tauroxes for each squad those are available), these are all options or requirements for the entry in question.

The fact that a dedicated transport is a separate unit counted as the same battlefield role and not taking up a foc slot(which formations do not use anyways) does not matter in the least. Dedicated Transports are a unit option, like certain weapons or unit leaders.

Part of the unit entry for Eldar Guardian Defenders is that they can take a Wave Serpent, so a defender host can have 3 serpents as long as they are taken as DTs(they cannot however simply be the fast attack serpents starting with any old unit inside).

As they are options for the unit entries dictated(or sometimes chosen) in the formation, they are a part of that formation, are units in that formation, and gain whatever benefits are applicable to that fornation(so yes, +1 bs to an aspect host wave serpent if that was the chosen benefit and the serpent is an upgrade for one of the chosen aspects)

Edit: stupid fat fingers on a smartphone.

Another interesting point is the Reclusiarch Command Squad Formation.

It has exactly two units in its official list. Just two: the Chaplain and the Command Squad.

In the datasheet provided for the Command Squad, it still allows it to take a Drop Pod, Rhino, or Razorback as a Dedicated Transport, just like Codex: Space Marines.

Then the Datasheet for the Formation says you must take a Razorback as a Dedicated Transport. That's right, the Formation TELLS you to do it. And unlike the Conclave of the Burning One, it doesn't state anything about this being otherwise illegal.