http://www.dakkadakka.com/dakkaforum/posts/list/69.page JForum - http://www.jforum.net
As a themed ally for my inquisition I have some questions.

1. What's the best way to run them as a combined arms detachment as inquisition are limited to the inquisitorial detachment.

2. Are the formations the way to go as they are very expensive points wise.. which puts me off.

Just for a bit of context I tend to run a couple inquisitors with a melee unit in a land raider crusader and acolyte squads to fill up the numbers ]]> http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8984505.page http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8984505.page GMT MT list needs the formation freebies to be even mildly competitive, but with INQ allies you could probably get them to work in a CAD as well a bit. As much as I'm a fan of Stormtrooper armies, the MT book is pretty bad.

An alternative you may want to look at is the IA12 DKOK assault brigade. It's another army you can build around Stormtroopers but that functions better as a cohesive army though it has no access to Valkyries or the MT specific wargear if you're jonesing on those.]]> http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8984519.page http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8984519.page GMT MT are kind of an odd choice as Allies since they overlap so much with what the Inquisition already does; they give you better elite infantry (a Scion is a point cheaper than an Acolyte with the same kit and he gets BS4, Deepstrike, and Move Through Cover out of the deal), but don't really help with range, volume, durability, Flyers...

I'd suggest either thinking of your army as a primary MT detachment first with an Inquisition detachment to provide psychic support and melee, and/or or look into Elysians/D99 (Forge World rules, but I've been playing them with normal 40k infantry and plastic Valkyries since there were plastic Valkyries) if you like airborne Guard since they offer a similar deepstrike/special weapon game plan to MT with a lot of extra flexibility and reliable Reserves.]]> http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8984520.page http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8984520.page GMT
The Tempestus was my preferred but they need a major renovation ]]> http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8984538.page http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8984538.page GMT MT have two main formations, Airborne Assault and a Taurox (sorry I hate that model) based one, although I don't have the, what is laughably referred to as a dex, at hand.

I really do like the concept but it is fairly dire in its current incarnation.]]> http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8984585.page http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8984585.page GMT
It is comprised of....

1 Taurox
1 Scion Sqaud (5-10 members)
1 Command Squad
1 Commissar

As long as the commissar is alive and the Scion Squad dies it immediately goes back into deepstrike reserve.

Since the commissar is an independent character in MT they can join anyone and hide. Ive had some success attaching him to large guard squads, conscripts, artillery units, and other hardy groups that need extra leadership (but his execution power does not work). I also find large squads of 8-10 can work better because you get more bang for your buck and they become a massive fire magnet. In addition you can load up the command squad with plasmas in the Taurox and have them go around and delete things. ]]> http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8985124.page http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8985124.page GMT
Scions themselves are overcosted, and lack abilities. What they do have is deep strike and AP:3 in abundance.

Some combos that might help.
- Servo skulls help Scions with one of their most significant weaknesses. Deep Strike Scatter.
- An Inquisitor in Termie armor can deep strike with scions.
- Scions provide good shooting, but have nothing in the way of psychics or assault, but Inquisition can fill in those holes.
- Inquisition can get access to lots of dedicated transports for cheap squads. If you flood the table with Vehicle chassis, you might help keep the Tauroxes around a bit longer, and have something left at the end of the game.1

I don't like the 2 big Scion formations because it forces you to put the entire thing in reserves, and the Scions can't deep strike. I really, really like the Hellrain brigade. It helps you overcome the fragility of Scions somewhat.

Personally, I think the combo is good thematically, and on the tabletop, but you do have to recognize the Militarum Tempestus are one of the weakest armies in 40K right now, and almost any other army would probably be more points efficient. ]]> http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8985512.page http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8985512.page GMT IMHO the formations are not the best, especially the flyers one. With different flyers, perhaps...
Also, what tag8833 said.

At which point range do you want to play? MT performs differently as a full (or majority) force at, say, 750 pts compared to 1850.]]> http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8985758.page http://www.dakkadakka.com/dakkaforum/posts/preList/706590/8985758.page GMT