I am Chinese, I may not express everything the way you guys do,
I came up with the idea that dodge is something more useful than hp when you are tanking. you can think of hp as a container filled with blood, the boss are taking it from the container while your healer are adding fresh blood by consuming their mana, as long as the healers don't go beyond your hp limit, the overall blood the boss can take is determined by how much blood your healers can totally provide. when compared to overall hp provided, your initial hp means nothing. but how you can make good use of the hp your healer provided is something can make you live longer. by, dodging more often or mitigating more damage dealt by boss.
but I am not a "professional" player, I just say things the way I feel. how you guys think about this? or why hp is important as it seems to be?