I was thinking about creating a bunch of 'chaos guardsman' clad in power armour just for some non-competitive games with friends. However, I was wondering how fluff-friendly this would be. Would it be possible for guardsman to wear power armour? (as sisters of battle are capable without the space marine implants). Would they be able to equip themselves with the heavier weapons like Missile Launchers and Heavy Bolters? (Heck, a normal guardsman would probably struggle with a normal bolter) Perhaps if they didn't have the shoulder pads, would it be more plausible (like giving them a 4+ armour save instead of the normal 3+).
Any help would be much appreciated