Druid from armor and stance have about 15-20% passive mitigation more than warriors and paladins. So if a druid takes a full hit ( no savage defense absorb) it will be 15-20% less than an unlocked hit on a warrior or paladin. So once you factor in savage defense and block average damage taken is about equal. Unfortunately healers hate healing druids because of the unpredictable nature of damage taken. Blizzard does not seem to care about spiked damage nor do they seem to understand why healers prefer to heal a tank that takes more overall damage (warriors and paladins).No comment on dks because they are in a really bad place.Personally to fix druid I have said this a number of times ... SAVAGE DEFENSE NEEDS TO BE REMOVED FROM IT'S EXTREMELY HEAVY DEPENDENCE ON VENGEANCE. To many dodges in a row means no vengeance stacks mead bad shields means masters value approaches zero as we increase dodge. And while warriors and paladins havd mastery approach zero as mastery and avoidance increase, they still need x amount of mastery to keep mastery at zero value, while for druid mastery will eventually be worth zero even with zero of it.