Not necesarily. My guild 2-tanks H Halfus. Me (druid) + Pally.
I take 4 drakes at the beginning. Paladin takes Halfus. I taunt when she gets high on stacks (by that time one drake is already dead, so I'll have Halfus+3 drakes), she taunts back after getting rid of the debuff. Then we finish off the remaining drakes. I then pull the last drake and just stay with it while everyone else focuses on killing Halfus :>
Good use of my and the healers CDs allows this :> Also, the pally Bubbles the first time she gets high on stacks. And if I get high on stacks, we have a Holy Pala that gives me HoP, and I use a cancelaura macro :>