Interesting, I am using 4hunters and 1 priest now and they tear it up in dungeons. So what is not working at 74? Not enough health? Too hard to heal? Are all pets tanks or just one? I run all pets tanks (bears and one pig) and I cannot pull aggro off them and my priest finds it pretty easy to heal as they fight for aggro. Once in a while a pet will die, but that's just because a few unlucky things going on. If I paid more attention they wouldnt, but its so easy mode that I just kinda lose focus.

edit: P.S. Priest is teh hax for healing. I have a bunch of AE healing ability and I have run a high level resto druid before and I have to say that I like the priest much much more. I run all pets in and just AE heal through most fights with my priest halfway between hunters and the pets. That way I ensure everyone gets healed (in case of AE damage)