You would think that but it is not the case. My tank is a Power Tech in not quite full BM gear and I get 5k crits on occasion. There are a lot of tanks as mentioned else where in this thread that spec tank and go full DPS gear except for the offhand. They are exploiting the current mechanics which allow them the higher hp and better survivability while not penalizing them in terms of DPS.
We routinely play in eight man premades. 1) Invite two groups of 4. 2) Get on vent or other voice chat program. 3) Countdown your queue, 3, 2, 1. When queue pops ask the other group if their pops via vent. If you both get in its an 8 man premade. If you don't you leave queue and try again. Winning 15 matches in a row is common....