Tried this technique with my hunter (on the same account as mage) who was level 62 at the time with most of the HFP quests still to do. It seemed quicker than mage as rather than having to do a spell with a cast time to damage the mob before the pets killed it, I was able to fire off an arcane/concussion shot from hunter...and cast a dot from lock. So this meant I caused some damage before the pets both charged over and finished it off. For some reason, the XP loss for kills seemed more like 75% here. Perhaps the mobs were of a closer level than the ones that the mage were killing. So last night I managed to go from 62 to 64 I want to get to around 70-72 then I'll shelf him for a while and go back to the mage.