acording to the "art of fallout 3" book, the combat armor is inspired by the look of US GIs during WW2 with a futurist look BoS doesnt look like the Space Marines at all, the only thing they have in common is power armor, the look of the Scribes is based in the monks of medieval europe(in fact they basically do the same thing) Chimera as OpposingFarce say is based in the mythical creature and is in fact not a transport and yes, the outcast only have one thing in common with the chaos forces, and is they departed from they "brothers" Fallout has less in common with Warhammer 40k than Warhammer 40k has with Starship Troopers