I suppose it's a bit like sound editing. We could have a category for Sound Editing and Sound Mixing, and some people, including myself, wouldn't be able to tell the difference. Hey, I didn't vote for Sound Editing this year cause I had no idea.
I suppose the same goes of Ensemble Cast and Casting. And if we had both, I suppose we'd have to give better guidelines to understand what we're voting for.
Anyway. I suppose I'm happy either way.