I am currently running a 10 man group. I have two identical 5 man teams consisting of 1 Prot Pally, 2 Arcane Mages, and 2 Holy Nova Priests. It's much slower leveling in dungeons as a full raid... the exp is about 1/4 what I get running each group alone... I think the fastest way to level two 5 man teams is to just alternate them.. level one team while the other gets some rested exp and then switch back and forth...