If a tank can manage with just Regen/Fairy at the start of a pull, then they can wear whatever they want as far as I'm concerned. A healer constantly dropping out of Cleric's to babysit you is also a dps loss, particularly on trash pulls.

Likewise, if you as a tank absolutely need stoneskin/adlo to survive a tank buster or it will one-shot you, then maybe you should reconsider your gear. Nothing below maybe AS3/4 should be one-shotting any tank.

SE just need to make VIT the primary damage modifier for tanks already, so we can all stop debating this and move on with our lives.