So, I am planning on making a witch hunters list for an upcoming friend-organized campaign (Orks and Death Korps don't seem to work well as allies). So, here is what I've scratched together in the past 15-20 minutes

Canoness, Power Armour, jump pack, Blessed weapon

Inquisitor-power armour, power weapon, hammerhand
-3 Acolytes, chirugeon, 2 crusaders
Callidus Assassin

10 Sisters, vet superior, book, heavy flamer, flamer
10 Sisters, vet superior, book, heavy flamer, flamer

6 Seraphim, vet superior, book, 2 inferno pistols
6 Dominions, vet superior, 2 flamers, 2 melta guns
Immolator, extra armour, dozer blade, holy promethium

There it is. I could, if necessary, drop the callidus for a pair of rhinos for the sisters...But I love the model and the themeatic viewpoint having an assassin at an inquisitors beck and call in addition to a mission of sisters of battle.

Tactics-sisters advance while ready to clear out enemy infantry, seraphim/canoness take out heavy infantry, and maybe a tank. Dominions react to whatever threat they meet, the inquisitor leads the 2 squads of sisters in the thick of the fighting. Last, the Callidus causes as much havoc as possible before charging at the juiciest target at 1k and (hopefully) go down with it.

So, I am planning on making a witch hunters list for an upcoming friend-organized campaign (Orks and Death Korps don't seem to work well as allies). So, here is what I've scratched together in the past 15-20 minutes

Canoness, Power Armour, jump pack, Blessed weapon

Why not get her frags, it does help a lot!

Inquisitor-power armour, power weapon, hammerhand
-3 Acolytes, chirugeon, 2 crusaders
Callidus Assassin

If you plan to have a melee inquisitor I would give him a familiar. In other case I would drop either hammerhand or power weapon. If you want to be a character killer maybe give him a force weapon, but do upgrade him to a lord. Give acolytes power armour or carapace so the majority armour is a bit better established and you can use the invulnerable save from crusaders. (im not sure how invulnerable would work with the majority save though)
If you like chirurgeons and want to make squad good for CC take two of them, power weapons and rockets will make this squad fold very fast.

Since you dont have a delivery system for the inquisitor maybe it is better to make him a dakka squad?

10 Sisters, vet superior, book, heavy flamer, flamer
10 Sisters, vet superior, book, heavy flamer, flamer

Im not a big fan of vanilla squads, but maybe heavy flamer and melta is a bit better since having two flamers and marching them across the board means that they will be wasting 2 shooty spots instead of one. I do like two flamers in a mechanized list though.

6 Seraphim, vet superior, book, 2 inferno pistols
6 Dominions, vet superior, 2 flamers, 2 melta guns
Immolator, extra armour, dozer blade, holy promethium
Me gusta holy promethium =)

There it is. I could, if necessary, drop the callidus for a pair of rhinos for the sisters...But I love the model and the themeatic viewpoint having an assassin at an inquisitors beck and call in addition to a mission of sisters of battle.

Tactics-sisters advance while ready to clear out enemy infantry, seraphim/canoness take out heavy infantry, and maybe a tank. Dominions react to whatever threat they meet, the inquisitor leads the 2 squads of sisters in the thick of the fighting. Last, the Callidus causes as much havoc as possible before charging at the juiciest target at 1k and(hopefully) go down with it.
I also think that tactic for callidus is not to kill the biggest baddest character, he excels at killing elite squads, not necessarily characters. Neural shredder is usually something I think about the most when I place him, it insta-kills marines and orc nobs!

Overall the marching list is interesting. Hope any of my babble helps.