I'd probably defect to the Tau empire. Their weapons are far better (play against tau if you don't belive me) and there ideals are far better i.e. actually allowing retreats when it's sensible instead of throwing men into the meat grinder and shooting them when there is clearly no hope. The only problem with that is i'd miss humanity as in women, socialising, but since were on about Imperial Guardsmen who never see home again anyway then For the Greater Good!