Warhammer 40k:Mixing Armies?

Question

Okay would it be wise when if I could mix Deamon Hunters with Steel Legion for Daemon Hunters to be the HQ or for Steel Legion to be the HQ...For Example would it be wise for the Imperial Guard to be my main army being supported by Gey knights or the other way around?

Answer 1

I guess it depends on what you have more of.  Probably makes more sense fluff-wise that a few daemon hunters would be helping a guard legion, and less that grey knights would just let some guard tag along with them.