Problem is, with the majority of boss fights, there are more DPS/healing/survivability checks than the actual skill requirement.

Titan HM is destroying DF groups because a double tank setup is going to have a hard time dishing out enough damage to meet the check on heart phase without auto-attacking for LB3 in phase one which is incredibly stupid, and even if they LB3 the heart, there's always the problem of tumult stacking which becomes mathematically impossible to heal through later on if your overall DPS is low enough.

"Grind more gear while we come up with more restrictive lockouts" is the universal solution to everything, and frankly, it's far from "fun".