Also a Prot Pally begin to solo aoe pulls well by 35 when you get Blessing of Sanctuary; and I would say this can translate to 2-3 versus elite mobs inside instances.

The way I would approach it is have the pally aoe tank, and have the 4 others help speed up the pulls.

Even if 5-boxing, I wont be pulling more than the efficient "con" level mobs. I try to kill level -2 to +0 of my tank's level, but 3 to 4 at the time.