Chan Island wrote:Been considering adding some sisters of battle to ally with my guardsmen. Turn it into a combined arms strike force with everything short of space marines. Thoughts? Good idea?
No reason why you shouldn't. SoBs fit in just well as any other imperial soup ingredient fluff wise.
The guard could have been called up to defend a cardinal world, the sisters could have been sent to bolster a push or they are both part of a crusade of faith some cardinal has dreamed up.
IIRC the sisters are the most inspiring of the allied forces the guard could end up working with.