I don't consider they did a pretty good job on the dps department of the tanks when DRK and WAR are basically the same job on they core and just have a small diferent mechanic on top of that wich is WAR generating more fell cleaves and DRK throw all his oGCD every 60s and the job don't have any real resource management considerating they just load MP without overcap it and shoot it in a almost perfectly determinated amount of time to just load and shoot every min.

On topic idk how well that active mitigation system from wow was and work but i agree that having all tanks mitigating the same way it's pretty dull and would love if they reform and add extra effects to certain mitigation skills so feel more fresh and unique mitigate damage with each tank.