You very well can I was considering doing such an army, a beleaguered Imperial World in desperate peril from chaos turns to the Ecclesiarchy for guidance and a rag tag band of priests resurrect an old warrior tradition donning ancient armor and standing with faith and bolters against the coming storm.
Just something I was toying with.
As for female marines is it really that big of a deal? I mean have we all devolved to the point of fluff nasi-ing ideas that we can't even allow the idea to exist? We cite old articles when GW could very well just flip the switch and we suddenly gain female marines. I just don't understand the concept of banning painters and converts for such things from tournaments it seems odd and foolish in every way, it is a personal choice no? If I buy Models and decide to convert them what gives people the right to say no if I were to try and register with them at a tourney?
It just doesn't make sense is my point, sorry bout the rambling. If you don't wish to play such a person, fine. But banning them from a tournament for such a thing is asinine.