DPS Enmity controls

[aodhan_ofinnegain]

So first off a tank instantly getting aggro back after losing it, by using provoke and ultimatum is bull, as it only gives +1 aggro over the next aggro lead so in an aggro creep scenario is absolutely pointless.
With the exception of WAR the other two tanks require one GCD to enter tank stance which sets aggro recovery back by a GCD, and if mid combo, there is further delay for aggro generation unless the tank uses out of combo aggro skill or have some aggro generation oGCDs skills ready to use. Even at that aggro generated at this point is pretty negligible to the point of needing to spam aggro combo a few times in some cases before it'll give an effective aggro lead.
In my experience most aggro creeps happen for 1 or 2 thing, the main tank dies lack of heals or CDs or just random stuff, so as OT need to pick up hate if I'm not second already, and second reason is mid combat DPS ain't using their tools for aggro.
Also disagree heavily with you opinion of it's squarely on the tank for aggro management, like DPSing and many other party synergies, aggro management is party effort no excuses around it. Just press your damn 120second CD every time it's off cooldown it won't kill you.