Yeah, I do like this idea, since I could imagine that Sinister probably doesn't believe in souls, or care if his Marauder/Nasty Boy clones are getting more unhinged over time.
I also like the notion that even the Celestial resurrection process that Apocalypse was using on the Dark Riders and Horsemen might have led to some degradation over time, which could explain why Poccy was always replacing them... Particularly in the case of the Inhuman Dark Riders, it would make sense that copies would possess less internalized terrigen, and manifest lower level abilities.
Maybe 'guns-for-hands' (Barrage?) used to be able to reform his hands into guns quickly and efficiently, and even turn his feet into blasters that allowed him to fly like a rocket, but over a half-dozen resurrections, his 'terrigen levels' have been so diluted that he can just barely convert his hands into blasters over the course of like, an hour, and so he has to walk around with gun-hands all the time, just to be useful and not be caught with useless human hands and no offensive abilities (on a ship full of 'survival of the fittest nuts!').