The space marines regularly have groups that splinter off from their ideology (soul drinkers) or renounce it entirely (see chaos), last I knew the dark Eldar are the ones who got corrupted by a chaos God but the craft world Eldar weren’t “created by a deity”, the orks are space fungus that have a psychic connection which creates their deities of Gork and Mork.

I can see how it can be interpreted that way and the gene seed is a really good point but I’m having a hard time making all the other connections. Even the inquisition has tons of characters that either change their ideology or side entirely.

That’s not at all what I picked up from it. Could you give an example?

I too am confused about the correlation since I’ve never run into nazis playing 40k. Though to be fair I run slaaneshi chaos so I don’t think I’m in their demo of black templars.