To William:

I think you misread that, or that it wasn't otherwise clear (rereading it, I'll just say I wasn't that clear). No tank should be dying solely to Gormok's melee damage, period. If they are, that's a sign that the tank isn't geared for the encounter or that there's something going wrong with the heal team or what have you. A geared and experienced tank on that encounter can die to a combination of Gormok's melee and Impale ticks as you describe, but I think you're undervaluing avoidance somewhat here as well. Decent avoidance isn't necessarily about avoiding that one hit that would otherwise have killed you -- it's about avoiding the chain of hits taken that forms the 50K health/2 second scenario you describe. To say that EH is the *only* means of surviving this is somewhat misleading, when a geared tank doing ToGC-25 is extraordinarily unlikely to be rocking less than 50% avoidance.

Where EH comes into play is a scenario Ciderhelm's previously described -- which is to say that over the course of a 3-minute or longer boss fight, the odds of hitting at least one bad avoidance streak are basically 100%. Ideally this doesn't happen in the midst of a nasty Impale tick, but sometimes it will. That's when EH is important, whether it's in the form of what you had walking into the encounter (armor/health, although -- as we've noted -- Impale ignores half of that) or the temporary form it assumes by way of a cooldown.