What I'm getting at (and I think LP is too) is that American Psycho is a very theme-heavy film, and those themes are all a commentary on Wall Street and yuppies. Take Bateman out of that context, and I'm not sure he feels right?
Halloween (the original one) is also a very thematically heavy film in some ways, but it's way easier to tangibly imagine Michael Myers in Smallville trying to stab a dude named Blackagar Boltagon.
I'm not sure that's something there's a "hard rule" for, but it's definitely something I feel like I have a sense for.
EDIT:
, but LP captured my thoughts well too.
But tangent aside, I'd definitely be interested in a draft if you have ideas. Even if he never gets run, drafting is a fun hobby on its own.