There are already two dps-tank jobs, please don't make Paladin the third.

[AI_wass]

To fix it, tanks need to mitigate more damage, deal less damage, dungeon mobs need to deal more AA damage, damage should be normalized so there isn't a magic vs physical tank, then poof you have a stronger tanking role.

That's well and all to say, but how do you make that fun and engaging within the confines of the current battle system?

This is the thing. It's not enough to simply say that the roles in a game, in any game, must be a certain way because of whatever arbitrary reasoning or tradition. If it's not interesting from a mechanical standpoint as well as a flavor/lore/role perspective, you're not going to find many players to populate that role; and at endgame, for pug content, tanks are rare enough as it is.