Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

Is there any in lore/in universe reasons why the Imperium maintains two different versions of one tank that do different roles but could simply be achieved by different ammo types?

Like I get the whole point of the guard, generally speaking, is mass infantry waves supported by different elements such as tanks and its clear that the leman russ takes inspiration from WW1 landslip and infantry support doctrines.

However it doesn't make sense to me why you would have a battle cannon firing one round and a vanquisher firing a different type for anti-armour when a long barreled Leman Russ could take both the HE for soft targets and some sort of AT round like a penetrator or HEAT style shell.

Not with standing Gdubs wanting to sell more models so breaking them down into different kits (prior to the new amalgamated Russ Kit) and in universe different varieties like the punisher and executioner having completely different weapon systems.

I recall reading a piece of lore (can't remember I'd it was homebrew or a small bit from FW imperial armour books) that discusses something about possibly a conqueror Canon and the mechanics developing a round from various bits of STCs that are similar to tandem warhead styles but turned out to be a pretty laborious task and didn't work as well as hoped.

Just intrested in hearing people's thoughts/views

Good old Imperial Ignorance is my guess, married to different barrel tolerances etc, or even bore.

The Leman Russ is a reliable design for a reason. Lascannon for anti-armour, heavy Bolters for infantry, Battle Cannon for general purpose.

The Vanquisher of course is more specialised.

Given the staggering scale of keeping the IG maintained, from a logistic point of view the resulting standardisation does make sense, as you only need worry about providing X Battle cannon rounds per Russ, Y Vanquisher cannon rounds per Vanquisher and so on.

A General in turn needn’t worry about “what mix of shells is going to be best for this engagement”, and the risks getting that wrong entails.

So in some books, regular LRBTs do have AP shells alongside the standard HE. However, compared to a dedicated TD vehicle like the Vanquisher it's not as good.
IIRC Vanquishers were also a more difficult variant to produce with only a few Forge Worlds even having the STC to produce them.
Think of it like the US Sherman. The basic tank is good but it had variants that performed different roles like the Easy 8 for AT, the 105mm variant for bunker busting, and then the various allied army variants like the Kangaroo or Firefly.

Leman Russ do have multiple ammunition types in use.

For rules simplicity, the ballistic cannon only have one firing mode in modern 40k. However, FW have released rules for alternate shell types in the past.

For example, Vanquisher cannon could fire the standard HE shell or the AP shell. In the editions that used these rules, Vanquisher cannons were a straight upgrade to standard Battle cannon with no downsides except points cost and rarity. They could also be equipped with coaxial weaponry that could increase accuracy and firepower.

Battle cannon had rules for firing HE vs AP, although their AP was less effective than the Vanquisher round. There is also an Infernus flame shell for hitting targets in cover, smoke shells, and ilumination shells for night actions. Rare Hunter shells are guided and can track a target and perform a top-down attack, but the FW producing them is lost by 40k, so very few are in circulation.

Conqueror battle cannons had an alternate Augur shell, which was a rare shell that sounds like a HESH round. The default Conqueror shell is a lighter version of the standard Battle cannon round, and the weapon is easier to fire on the move accurately.

Canonically, there are multiple versions of these shells. For example, the image of an AP shell in Imperial Armour is a Mk12 shell, suggesting at least 11 other variants are in use. The Mk12 includes a small explosive charge fused to explode after penetrating, but apparently most Leman Russ AP shells are simple kinetic penetrators.

The best details for all this were in Imperial Armour Volume 1, 2nd edition, which contained rules for using them. The lore is available in the Warhammer + Vault if you have a subscription.

Post edited to correct info after checking IA1, 2nd ed.

I've had Warhammer + for a while now and stupidly didn't even know I could access the books online for the subscription price... oops!

That makes sense with the Sherman Analogy and the general techphobia/reverence, whatever your views are on the innovation of the Imperium as a whole.

I still think logistically, an imperial commander would face the same issues regarding tank types/variants as they would with the shells I suppose. Having multiple different specialised variants of tank but maybe not enough vanquishers or more widely produced AT versions in the right place, whereas every russ with a variety of shells could at the very least hope to deal with different threats with their relevant munitions.

Intresting information about the Auger shell! Definitely going to have to read the Imperial armour books when I get the chance now.

Begs the question if the Imperium has access to other similar smart styled munitions. Although I get that their whole identity is based on less modern and dare I say it backwards tactics!

Certainly some intresting food for thought for a more modern styled regiment/planet with ready access to madvanced or provisioned forgeworlds

cmurphy96 wrote:
I've had Warhammer + for a while now and stupidly didn't even know I could access the books online for the subscription price... oops!

That makes sense with the Sherman Analogy and the general techphobia/reverence, whatever your views are on the innovation of the Imperium as a whole.

I still think logistically, an imperial commander would face the same issues regarding tank types/variants as they would with the shells I suppose. Having multiple different specialised variants of tank but maybe not enough vanquishers or more widely produced AT versions in the right place, whereas every russ with a variety of shells could at the very least hope to deal with different threats with their relevant munitions.

Intresting information about the Auger shell! Definitely going to have to read the Imperial armour books when I get the chance now.

Begs the question if the Imperium has access to other similar smart styled munitions. Although I get that their whole identity is based on less modern and dare I say it backwards tactics!

Certainly some intresting food for thought for a more modern styled regiment/planet with ready access to madvanced or provisioned forgeworlds

I edited my post whilst you were typing- Hunter rounds are the smart munitions, Augur rounds are just HESH (although their schematic looks like HEAT).

Other smart munitions do exist, but they seem to be rare and generally only found in missiles. The Hunter shell is specifically noted as using a similar logis engine to hunter-killer missiles, so they are basically tank-fired anti-tank missiles.

The Vault is the best bit of Warhammer + IMO The viewer is unfortunately crap though.

cmurphy96 wrote:
Is there any in lore/in universe reasons why the Imperium maintains two different versions of one tank that do different roles but could simply be achieved by different ammo types?

Like I get the whole point of the guard, generally speaking, is mass infantry waves supported by different elements such as tanks and its clear that the leman russ takes inspiration from WW1 landslip and infantry support doctrines.

However it doesn't make sense to me why you would have a battle cannon firing one round and a vanquisher firing a different type for anti-armour when a long barreled Leman Russ could take both the HE for soft targets and some sort of AT round like a penetrator or HEAT style shell.

Not with standing Gdubs wanting to sell more models so breaking them down into different kits (prior to the new amalgamated Russ Kit) and in universe different varieties like the punisher and executioner having completely different weapon systems.

I recall reading a piece of lore (can't remember I'd it was homebrew or a small bit from FW imperial armour books) that discusses something about possibly a conqueror Canon and the mechanics developing a round from various bits of STCs that are similar to tandem warhead styles but turned out to be a pretty laborious task and didn't work as well as hoped.

Just intrested in hearing people's thoughts/views

theirs a few reasons

One is the simple SCALE of the imperium. local variations of "standard" designs are found everywhere- look at all the different lasgun patterns for example, so having several versions of the Leman russ is quite understandable (most of the alternate weapons on the Russ kit were originally separate tank datasheets that got folded into the standard LRBT sheet). given the rather fractious and feudal nature of the Imperium, its quite likely that some forge worlds produce "their" variant purely for prestige and political reasons as much as for practical requirements


Another is in universe logistics. High velocity, Large bore cannons have historically been something of a bottleneck in tank and warship production, and the Vanquisher cannon is somewhat harder to make (it was originally a rare variant only built on a few forge worlds). The Guard is explicitly built along attritional lines of "overwhelming numbers of good enough units", so having 30 regular battle cannons is better for them than 15-20 vanquisher cannons. theirs also questions of ammo supply as well, if the high penetration shells used by the Vanquisher are significantly harder to make, for example (this was historically a issue during ww2, that the high AP tungsten cored rounds were rare due to limits on the supply of tungsten).


Another possible reason is the expected target types. the vanquisher is, in current rules, unable to generate any blast effects, which makes it less useful against dispersed infantry targets. against some enemies like orks and tyranids, the extra anti-infantry ability might be more useful. indeed, the standard battle cannon is something of a "generalist" option, giving OK anti-horde, anti-power armour and anti-vehicle effects, while specialist options for each exist that excel at one at the expense of the others.

same reason it happened in real life.

another gun would do the AT job better.
the US could have just had 1 tank/tank destroyer gun, but instead they armed most of their tanks with a 76mm gun and their tank destroyers with something bigger.

The Vanquisher Cannon supposedly differs from the basic Battle Cannon quite much. I think the first Imperial Armour talks about this, and it even makes a big deal about the weapon being super-difficult to produce because it is so high-tech-something.

Here is how I imagine it: the Vanquisher Cannon is a type of coil gun that uses trans-magnetic (space magic) accelerators to fire a special two-stage round; this round has no propellant and it is made up of an outer sheath and an inner adamantine sabot. When the cannon is fired, the accelerators partially melt the outer sheath, turning it semi-liquid, so upon impact it "splashes" against the target and releases the inner sabot. The purpose of this is that the splash overwhelms layered defenses (like force fields) and allows the sabot to slip straight through them without losing velocity (as the sheath absorbs the impact force). Hence no invulnerable saves. You obviously don't fire this thing out of a Battle Cannon and don't feed the Vanquisher Cannon with anything else either unless you want it to blow up.

So I just caught up with I think Volume 2 Imperial Armour and what a fantastic little snib of lore and plenty of options for paint schemes and such.

I get the idea that the Guard tanks in particular are based on World War 1 and 2 tank, doctrines and design philosophies. They use all infantry support, medium, heavy tanks and all Myriad of specialised variants. Also the in universe aversion to innovation and designing things that aren't already STC fragments would mean they don't develop new or unmade things.

In my head it personally makes more sense to develop different munitions over entirely specialised tanks but I'm certainly thinking of things from a more modern approach to armour and arms in general which certainly isn't in the realm of WH40k haha

it is also worth remembering that the Imperium's technology is schitzotech derived from mixing parts of recovered blueprints, all being built by technology worshippers who consider innovation to be blasphemous. sure, you could probably just make a longer barrelled battle canon and get most of the same effect as a Vanquisher.. but the holy blueprints specify a short barrel, and suggesting that the holy plans could be improved on by the likes of mortals is heresy, and anyone who even suggests such a thing gets recycled into a servitor. but look, we have a holy STC fragment for something called a vanquisher cannon. while meant for a bigger vehicle, its breach and ammo can fit into the same mounting as a Russ's battle cannon and ammo bins, so we'll use that instead! oh you say, why can't we just mount one of the baneblade mega battle cannons on instead? because then we'd have to alter the holy blueprint of the Russ turret to make it fit.

cmurphy96 wrote:
Is there any in lore/in universe reasons why the Imperium maintains two different versions of one tank that do different roles but could simply be achieved by different ammo types?

Not really. If you go back to 2nd ed., the Battle Cannon firing what were clearly HE rounds had decent armor-penetrating capability because the template "hit" every location under it. Thus, even against another Leman Russ or a Land Raider (it's only likely peer opponents) it could get a penetrating hit on track or sponson. There was also a hull-mounted lascannon.

I never heard a single person complain that the Battle Cannon was deficient against vehicles.

What happened was 3rd edition, with it's simplified (and tougher) armor levels. All of a sudden, the Battle Cannon inadequate.

How then to fix this problem?

The obvious solution was to have an option for the ordnance template and one to just punch through armor. But that doesn't sell models, so it was rejected.

Much easier to make variant ammunition than run two sets of guns and differentiated optics, etc.

The real-world equivalent is not the Sherman vs German armor, but the Sherman vs Japanese armor.

On the last post about 3rd Ed?

Do keep in mind that the Vanquished came from Forge World, and so was “officially unofficial”, particularly as at that point, it was a Battle Cannon which could shoot AT rounds as well.

It did of course later receive a plastic kit and so become Proper Proper.

That was around 2009-2010. But I’m afraid I couldn’t tell you if the Codex rules preceded the model or not.

Trying to make 40K lore make sense can be a little tough sometimes. The books also have little inconsistencies.

Still, I find the Sherman and its variants analogous to the Leman Russ and its variants. The Sherman with the standard 75mm had anti-tank and high-explosive rounds. The AT rounds lacked sufficient performance as the war progressed. The Sherman Firefly with its 17 pounder could fire anti-tank rounds with outstanding penetration, but the tank had to be redesigned to take the gun (different turret and no bow MG gunner). The shells for the 17 pounder were very large, able to contain more propellent and thus granting more muzzle velocity that the long 17 pounder barrel could use to impart all that force on the projectile. As as aside, the 17 pounder did have an HE round, but it was noted as being inferior to the "short" 75mm HE.

The 40K books speak of the Vanquisher Battle Cannon being difficult to manufacture, so its comparatively rare. I imagine that it has a bigger breech in addition to the longer barrel taking larger shells with more 40K-era propellent in addition to a specialized projectile. Perhaps the standard Leman Russ has AT and HE rounds for its battle cannon, but the AT rounds lack the penetrating power.

Anyhoo.

 Mad Doc Grotsnik wrote:
On the last post about 3rd Ed?

Do keep in mind that the Vanquished came from Forge World, and so was “officially unofficial”, particularly as at that point, it was a Battle Cannon which could shoot AT rounds as well.

It did of course later receive a plastic kit and so become Proper Proper.

That was around 2009-2010. But I’m afraid I couldn’t tell you if the Codex rules preceded the model or not.

Of course, because GW loves creating problems in the rules than can only be solved by having the players buy more models.

Which are then retconned into the lore.

So yeah, we can talk about how Vanquishers are like Sherman Fireflies, or the later 76mm versions, but that's not really accurate because there is no arms race in the 41st millennium. It's not like the Orks have a new and innovative vehicle rolling off the assembly lines. GW decided to create design space for more tanks because they sell well, so now we have to pretend that the monolithic Soviet-style one-size-fits-all Imperium with only four vehicle templates has a multiplicity of designs in dizzying configurations, including one that lacks a floor plate.

Leman Russ Vanquishers have existed since at least the beginning of 3rd edition and I think 2nd edition in the first Imperial Armour book, they are hardly a recent invention by GW. Rules were featured in the first Imperial Guard codex of 3rd edition, although limited to 1 per army. They disappeared in the second codex of 3rd edition, and were then reintroduced in the 5th edition codex alongside the new Leman Russ kit with Vanquisher parts.



The original pattern was produced by the Tigrus forge world, which was lost to Orks. Subsequently, Stygies VIII and Gryphonne IV both attempted to replicate the design with some success, producing slightly different weapons. The design shown in the 3rd ed codex above looks very similar to the Gryphonne IV weapon and is probably this pattern.

There is also a Mars-Alpha pattern, although this may refer to the hull only, leaving the cannon as an unknown pattern. It is very similar to the Gryphonne IV pattern, but the turret-end of the barrel is a little different. As Mars is supposed to hold copies of all STC variants, this may be the original Tigrus Vanquisher.

The current plastic GW model is an unknown pattern to my knowledge, but presumably either Tigrus or Mars for the aforementioned reasons. It has visual similarities to both the Gyphonne pattern and Mars-Alpha pattern, but is shorter.

Vanquishers being unable to fire HE shells is purely a result of current rules balancing (to create distinct roles) and not reflected in the lore, where Vanquishers can fire HE.

Local forge worlds producing cosmetically-different-but-functionally-similar vehicles based on the particular STCs they hold is not against the lore. The Imperium is not a centrally-planned economy like the Soviet Union was supposed to be, it is a feudal state with a few core laws centrally enforced and a bunch of otherwise-independent fiefdoms that agree to abide by those laws in return for protection. Everything is fragmented and their technology is based on archeological fragments mashed together into functional Frankenstein monsters of tech. The Departmento Munitorum tries to standardise as best it can, but there is a limit to what can be achieved from such a disparate empire. If weapons or systems are more trouble than they are worth, the Departmento Munitorum mothballs them into stockpiles like the Malcador tank and variants, which are only brought out in extremis or for specific tasks.

Gryphonne IV pattern:


Stygies VIII pattern:


Mars-Alpha pattern:


Plastic kit with unknown pattern:

I think my personal favourite Vanquisher models are definitely the forgeworld ones, the proportions of the guns are ridiculous in typical Gdubs fashion but they at least have the length and a semi believable Ammo bustle.

Don't get me wrong, from a purely gaming/model perspective it's great to have the variety, just thought it was intresting that the Imperium clearly has the capacity to make some awfully effective munitions and it would be simpler to have one MBT style tank weapon with multiple different rounds for different threats.

The imperial armour breakdown of the different rounds was a great read from a lore perspective

That being variety is the spice of life especially when it comes to little plastic soldiers and tanks haha

The pattern of the Leman Russ that we have a plastic kit for is the Phaeton pattern.

Tygre wrote:
The pattern of the Leman Russ that we have a plastic kit for is the Phaeton pattern.

Ooh, do you know where this was stated? I'd like to read more about this.

 Haighus wrote:

Tygre wrote:
The pattern of the Leman Russ that we have a plastic kit for is the Phaeton pattern.

Ooh, do you know where this was stated? I'd like to read more about this.

The schematic for the Russ, that fits the plastic version, in Imperial Armour vol1 is labelled Phaeton pattern (page 15). I have heard it mentioned before also, somewhere. Gryphonne and Stygies had vanquisher turrets from forgeworld. And Mars and Ryza had alternative turrets for the common Russ from Forgeworld as well.

Tygre wrote:

 Haighus wrote:

Tygre wrote:
The pattern of the Leman Russ that we have a plastic kit for is the Phaeton pattern.

Ooh, do you know where this was stated? I'd like to read more about this.

The schematic for the Russ, that fits the plastic version, in Imperial Armour vol1 is labelled Phaeton pattern (page 15). I have heard it mentioned before also, somewhere. Gryphonne and Stygies had vanquisher turrets from forgeworld. And Mars and Ryza had alternative turrets for the common Russ from Forgeworld as well.

Thanks!

Tygre wrote:
The pattern of the Leman Russ that we have a plastic kit for is the Phaeton pattern.

This only fits for the pre-5th edition leman russ.


Automatically Appended Next Post:

 Haighus wrote:

There is also a Mars-Alpha pattern, although this may refer to the hull only, leaving the cannon as an unknown pattern.

Pretty sure all turrets of that type are Ryza turrets. The hull is Mars pattern.

The exact same reason RL Sherman had long AT 75 mm gun or the shorter, HE firing 76 mm gun (in 1:3 ratio) - because long, straight, precise barrel for anti-tank sniping is expensive and 80% of the time, short one will do so why overpay? Conversely, you don't want to wear out said long, expensive and accurate barrel firing cheap HE ammo, so the infantry support was left to 76 mm armed Shermans with cheaper guns/ammo. And these were so successful that toward the end of the war, the ratio was tending more towards 1:7 (though to be fair with Nazi tanks going nearly extinct by 1945 the 75 mm gun simply had too few good targets to justify expense and was mostly used to snipe strongpoints and such from long range).

And USA wasn't the only country doing this in WW2, see German Pz IV with short, infantry support 75 mm gun or long, AT role 75 mm. Then you have Russian IS-2 with long AT guns (85/100 mm) or short 122 mm - same deal, except even more pronounced...

I could be wrong, but wasn't the Sherman,75mm gun if not unique, at least unusual in having effective HE and AT rounds? Most tank guns leaned harder one direction or the other.

the LRBT is a tough one, because the model's gun caliber is laughably huge, so I think we're pretty squarely in fantasy land when talking about it's ammo.

My choice of the Sherman had nothing to do with combat effectiveness or similar guns but more with the idea that it was something people could picture quickly as having many variants while maintaining the majority of its basic structure.
For example, below we have a basic M4 Sherman, an M10 Tank Destroyer, an M7 Priest, and the Canadian Kangaroo APC:

They're all very clearly Sherman based while having drastically different arms or battlefield roles.

 Polonius wrote:
I could be wrong, but wasn't the Sherman,75mm gun if not unique, at least unusual in having effective HE and AT rounds? Most tank guns leaned harder one direction or the other.

The problem with HE Sherman ammo from long AT gun was that it was both much more expensive than short cannon one (thanks to smaller economy of scale) and also much less effective - short cannon means lower projectile speed and smaller forces acting on shell, so you can make walls of shell thinner and fit more explosive inside, and that's with comparable size guns. Simply not cost effective.

But they don't need to be comparable, because shorter, lower recoil gun also means smaller recoil mechanism, and you can use weight savings to fit bigger gun in your tank instead. For example, 1940 German AT gun was 5 cm vs 7.5 cm HE one, or the above 1944 IS-2 example. That's why infantry support tank concept was so attractive, you could have much bigger bang for $ spent (and conversely, that's why USA invested so heavily into tank destroyers in WW2, because they tried to field big, heavy AT gun comparable in size to regular HE one by saving weight in thinly armored, roofless vehicles instead).

cmurphy96 wrote:
I think my personal favourite Vanquisher models are definitely the forgeworld ones, the proportions of the guns are ridiculous in typical Gdubs fashion but they at least have the length and a semi believable Ammo bustle.

Eh, no. It's way too short to realistically fit shells. It suffers from usual FW problem of having the right concept, but bad execution of it.

Don't get me wrong, from a purely gaming/model perspective it's great to have the variety, just thought it was intresting that the Imperium clearly has the capacity to make some awfully effective munitions and it would be simpler to have one MBT style tank weapon with multiple different rounds for different threats.

I disagree. That would be way too expensive and simply won't fit Imperial doctrine favoring mass over quality. SM or Sisters can employ the concept, but it's simply not how IG does things.

You can even see it in RL, where NATO went for high quality guns, which made the tanks so expensive the average tank force of a country is tiny. Russia, on the other hand, went for bigger, 'good enough' HE guns, which made them far cheaper and more effective in infantry support role (and the tanks costing 1/3 as much) - then funnily enough, fixed the AT drawback/lesser accuracy at extreme ranges by having guided anti-tank missiles fitting inside the bigger barrel of 125 mm gun to use them on distant stuff giving them unparalleled accuracy and killing power (because at 5 km, AT missile unlike unpowered projectile loses nothing of its effectiveness). If anything, this is the model Imperium should use, but GW based IG tanks on WW2 doctrine so it is what it is.

It's also funny seeing hand wringing about Russians giving 60s era T-64 tanks to second rate units now, when said T-64 can fire 2022 models of gun missiles making it just as deadly as any tank on the planet right now, when on the opposing side, Leopard 1s from the same period are stuck using guns and ammo that was maybe good in 60s but is complete garbage now. Long expensive AT guns are simply much more vulnerable to progress and doctrine changes making them obsolete, while bigger support role guns can be upgraded much more cheaply using better ammo, and that's what Imperium is doing with their LRs.

 Irbis wrote:

 Polonius wrote:
I could be wrong, but wasn't the Sherman,75mm gun if not unique, at least unusual in having effective HE and AT rounds? Most tank guns leaned harder one direction or the other.

The problem with HE Sherman ammo from long AT gun was that it was both much more expensive than short cannon one (thanks to smaller economy of scale) and also much less effective - short cannon means lower projectile speed and smaller forces acting on shell, so you can make walls of shell thinner and fit more explosive inside, and that's with comparable size guns. Simply not cost effective.

But they don't need to be comparable, because shorter, lower recoil gun also means smaller recoil mechanism, and you can use weight savings to fit bigger gun in your tank instead. For example, 1940 German AT gun was 5 cm vs 7.5 cm HE one, or the above 1944 IS-2 example. That's why infantry support tank concept was so attractive, you could have much bigger bang for $ spent (and conversely, that's why USA invested so heavily into tank destroyers in WW2, because they tried to field big, heavy AT gun comparable in size to regular HE one by saving weight in thinly armored, roofless vehicles instead).

right, the original 75mm gun was mainly HE, with decent (at least in 1942) AT. the later 76mm had a longer barrel, and better AT, but less effective HE, and due to American doctrine, Shermans weren't meant to be the main weapon against enemy tanks.

The whole LRBT with the all rounder and the vanquiser with the good AT is almost literally the situation with british Shermans, who mounted the 17 pounder gun in mixed squadrons as the firefly.

 Polonius wrote:
due to American doctrine, Shermans weren't meant to be the main weapon against enemy tanks

Sidenote, while this is technically true, the doctrine was based on wishful thinking of officers completely new to the whole armored war concept. Reality verified it rather harshly quickly. Then you have the above-mentioned lack of Nazi tanks to shoot which led to even bigger warping of the concept and using both tanks and tank destroyers in really weird ways that went completely against said doctrine.

Also, HE guns aren't necessarily bad against armor - Soviet WW2 122 mm guns technically didn't shoot AT ammo but explosion was enough to rip off turrets from lighter tanks or shatter armored plates of heavier ones (helped by really bad quality of German steel by that point) killing everyone inside with pressure and shrapnel. I wish that was somehow reflected in 40K rules (say, normal LR having worse AP but dealing more damage on failed armor save, but alas, that went out of the window with 4584723 damage Railguns and other idiocy that eventually led to Vanquishers being warped also). I am not sure how I would do that (AT guns dealing unspillable mortal wounds against single target instead of normal damage, maybe, or chance to simply kill target on say 5+?) but I wish rules were closer to fluff...

 Gert wrote:
They're all very clearly Sherman based while having drastically different arms or battlefield roles.

Except funnily enough what you linked is clearly earlier M3 based Priest/Kangaroo (note riveted construction, suspension, and bent front chassis), not the later M4 one And in any case, I dunno if I'd call them 'Sherman based' as while yes, they did share some hull parts all three had paper thin armor compared to 'real' Sherman, and overall they had much less in common than say different Chimera or LR based vehicles in 40K.

 Irbis wrote:

 Gert wrote:
They're all very clearly Sherman based while having drastically different arms or battlefield roles.

Except funnily enough what you linked is clearly earlier M3 based Priest/Kangaroo (note riveted construction, suspension, and bent front chassis), not the later M4 one And in any case, I dunno if I'd call them 'Sherman based' as while yes, they did share some hull parts all three had paper thin armor compared to 'real' Sherman, and overall they had much less in common than say different Chimera or LR based vehicles in 40K.

Eh, the Leman Russ chassis is also used for the Atlas recovery vehicle (which has little armour), Collossus Bombard, Destroyer tank hunter, and Thunderer. All of these are as different to the basic Leman Russ as a Priest is to a Sherman.

Chimeras have even more variation, with the basic IFV, a group of fast flame tank variants, multiple turreted and un-turreted self-propelled artillery, turreted AA variants, open-topped scout vehicles, multiple-missile launchers, mobile ICBM launchers, and an unarmoured utility workhorse vehicle. The lore has examples upgunned to fill the same role as Leman Russ and tank destroyers too. Thats a lot of roles and significant differences in design across them.

 Irbis wrote:

 Polonius wrote:
due to American doctrine, Shermans weren't meant to be the main weapon against enemy tanks

Sidenote, while this is technically true, the doctrine was based on wishful thinking of officers completely new to the whole armored war concept. Reality verified it rather harshly quickly. Then you have the above-mentioned lack of Nazi tanks to shoot which led to even bigger warping of the concept and using both tanks and tank destroyers in really weird ways that went completely against said doctrine.

Well, there's a reason that tank destroyers didn't really feature in the post war doctrine. The Medium tank evolved into the Main Battle Tank, and, at least until guided AT rockets, was basically the biggest threat to other tanks. Tank Destroyers were based on the idea that the germans would have masses of tanks, which on the western front they rarely did. So they got used as infantry support and other nonsense. To bring it back to 40k, Vanquishers are great against enemy land raiders, but against Cultists or orks or plain old rebels, the battle cannon is simply going to be better most of the time, and good enough the rest.

But everybody's armored doctrine was flawed early in the war. And even if you planned your doctrine around the battle of France or early Barbarrosa, those conditions never really existed again. and the US wasn't fixed in the mud as a rule. they spent the war constantly upgrading bigger ticket items than the tank: the Iowa Class Battleships, the B-29, and obviously the Manhattan project were all enormously expensive projects meant to leapfrog current tech levels. the problem with tanks was that the US didn't want to build anything heavier because it would become too difficult to transport to and around Europe. By the time the Big Cats were really in force, the allies had air superiority and were broadly on the offensive on all fronts. Germany's tank programs past the Panzer IV were kind of like the Iowas: incredibly expensive and had minimal impact on the war. the only problem was that the US could afford to pour resources into programs like that, and Germany didn't.