Okay... So, taking this to ridiculous extremes (but hey, it's not as if I've got anything else to do!)...
Harvey Dent. We have two Harvey's, Keaton universe Billy Dee and Kilmer universe Tommy Lee (as far as I know they're supposed to be the same guy, I've never seen anything to say otherwise).
Soooo... that must mean there are
two Keaton Universes and
two Kilmer universes; a Keaton universe with a Billy Dee Dent and a Keaton universe with a Tommy Lee Dent, and a Kilmer universe with a Billy Dee Dent and a Kilmer universe with a Tommy Lee Dent.
Edit: Thinking about this even
more... Given that Clooney is supposed to be the same Batman as Keaton (and therefore, Kilmer), there must be two Clooney universes!! One that had a Billy Dee Dent in his past, and one that had a Tommy Lee Dent!