How much difference in damage should the tanks have?

[Oizen]

0% to none, preferably.

Issue with doing that and nothing else is that in an environment where every tank does the same ammount of damage, then the Tanks who have additional utility will always be meta and the ones that don't will be left in the dust. DRK and GNB don't get to function as 3rd healers like WAR, so if WAR is hitting as hard as them, why bring DRK or GNB?

In which we'd be forced to make them all have the same defenses too, in which we'd get even closer to having exactly 1 tank class with 4 different cosmetic options

The balance of this game is actually REALLY bad and has been for a while, its just that the majority of content is so easy that no one notices.