Well it kinda does, if ur say 17parry/17dodge and 45% block with 139k ur gonna survive more then some1 with 9dodge/11parry and 40block and 159k that extra 20k HP is gonna do crap all compared to several 100% avoidance dodges or parrys. To give you an idea thats the 2 tanks in our guild and the 'avoidance' tank took 50% less damage on most fights. After the logs lets just say one of the tank re-gemmedavoidance just can't guarantee that.
Dont get me wrong stam is important, but 20k more HP aint gonna save ur life but stackign 14% or more avoidance split between parry n dodge will