As a healer ive had the opposite issue with tanks that think they are gods gift to the world.

I just got my WHM to 52 ilvl 120. I am doing level 50 hardmode dungeons and nearly every tank I get insists on pulling the whole map. I announce at the start, First time, ilvl120.

Still get my ass chewed because they die in under 1 second. It's mostly down scaled DRK tanks that get killed. If its one of the other two tank jobs I can generally handle healing the big pulls.

But ya im sick of the lets go fast and pull the whole map when neither the tank or the rest of the group is up to it. Guess what level 60 DRK's with ilvl 180.... you get scaled down to 110 in those dungeons and lose critical skills you normally have at 60. The other 2 jobs can actually mitigate that damage and sustain.. you cant.