The two tanks have the same effective HP, and nearly the same effective healing received. There's no secret sauce synergy between one healer and one tank or the other healer and the other tank. Healers do the same things with (nearly) the same effects for pretty much every situation except for Hallowed Ground vs. Holmgang.

They're balanced. They've both viable, capable, in demand, useful, etc. for everything. Pick the one you like and don't stress.