I don't know about you guys, but as of recently healer aggro has been a huge issue for me. I really think there should be a nerf as aggro gets pulled off of me constantly and our healers get 1 shot. I don't know if this is balance issues with druid aggro in specific but it's quite insane. Please nerf.
If healers are out aggroing tanks then something is very wrong. The only chance that could happen and not be a total fuck up is when multiple adds spawn and that is easy to fix. Healer stays aware of spawn timers and doesn't blow big heal cds if they do they use whatever ability they have to drop threat and tanks pick up adds quickly and taunt as needed. If it is a resto druid pulling threat then root them and step away.
Beware of the man who works hard to learn something, learns it, and finds himself no wiser than before... He is full of murderous resentment of people who are ignorant without having come by their ignorance the hard way. -Kurt Vonnegut, "Cat's Cradle"
I do not know Druid tanking in the slightest, but first thing that popped to mind was are you hit/expertise capped as a tank(if applicable to you as it is all other tanks). The only time my two tanks have any sort of threat issue is when I intentionally have Righteous Fury up to direct bats to my location(which is by one of the tanks) on Tortos. Beyond that, even with RF up our Monk and DK have no issues. Our Monk can actually peel threat from the DK if he intentionally tries to.