I'm currently using druid tank, currently level 46 and so far I have no issues holding threat on large 10+ pulls. I'm using Druid tank, priest, 2 mages, and a warlock. I know having 3 mages would make killing stuff even faster, but I love being able to summon my tank back after sending him back to town to sell junk and get right back to dungeon crawling. The utility of the warlock far outweighs anything a 3rd mage would bring to the team imo.

I really don't know how this team will hold up up in end game dungeons like a full BRD, BRS, DM and such. But thorns, roar, and a couple hots pre pull seem to be enough to hold threat so far. Pretty much a one button tank so far, literally just spam roar for a bit before starting AoE and the tank holds everything.