When it comes to pug content, and to a lesser extent raids depending on your relationship with your healers, its your respnsibility as a tank to adapt to your group, not the other way around. Everything you do either boosts or gimps your teammates' ability to maximize their performance, regardless of inidividual player skill ceilings. If you queue into a dungeon and see your healers and/or dps are undergeared it is 100% YOUR responsibility as the tank to set an appropriate pace for the run. If a tank overestimates pugs and dies they've got no one to blame but themselves.