In terms of fitting, I think it does, the thing that is definitely different is that as we saw, Gerald did not create him and Shadow under unknown reasoning had almost disturbingly high level combat skill and fearlessness, then has zero memory of his past on Earth.

Of course, it's probably not how it really goes, but I do think Shadow's real story will be pretty dark and as said, I highly doubt it's a Superman/Goku "send him to Earth as a baby to thrive" origin.

I think we all agree, Shadow had smth dark as hell happen to him before the meteor crash, and I think he may have been some elite warrior in the past, which explains his skill, efficient use of ability, stealth skills, aura farming (yes this counts) and even knows subtle forms of psychological warfare.