User blog comment:SonOfZeus1200/The Camp Half-Blood & Kane Chronicles Series will collide!/@comment-3566131-20120522023546/@comment-5112532-20120530175330

Yeah, exactly, it would get way too complicated.

The Roman and Greek cross-over is logical, as they are the same gods with slightly different aspects of their personality.

Also, what would they fight about..? It would just end up as Carter, Sadie etc. VS Percy, Jason and co. over which set of gods are better, or something silly like that. Nothing that would make a great story line, unless RR would try to mirror the clash between Roman/Greek and Egyptian cultures, when actually the Romans accepted some of the Egyptian gods into their mythology (I think).

It's fun to hint at another set of gods, but I think that its merely to fuel our imagination. :)