You really do think about Oddworld an aweful lot, don't you? And the things you come up with - wow, they're all so...um...erm...er...original (yeah, that't do, I guess). Hehehe, just kidding.
Um, I dunno. Lorne has insinuated that one of the heros may be a queen (which certainly begs the question of how do we control her in game, among others), which are large animals. I hope the heros don't turn out to be just a serious of linear progressions - like each hero having his/her own moon is bad enough, but if there's a trend to all the characters, that would just be too corny and forced, in my eyes.
I suppose I'm also thinking about this rumoured half-monkey, half-horse centaur. Do you want to apply your theory to this guy? We don't know if he's actually one of the five saviours (we don't know if he's for real, or just a joke, even), but in my mind he's horse-sized, which would be bigger than Abe. Whether he's 'higher' or 'lower' than Munch, I dunno, although I can't help wondering if there'd need to be two seperate rings, one for this guy, one for his boat. Maybe?
I haven't really speculated like this before, so forgive my rambling style. It's just so much more fun than doing homework, y'know?