They are all fairly equal but it basically depends on what build you make. For tank build, wizard has the resist advantage as well as skullshields for damage and damage reduction, warrior can have AR advantage and rogue can be annoying if its a swap rogue or so. Wizard barrage is also powerful for damage reasons.
Warrior can be good for battlemage tank build like wizard but they can use shield to increase offhand of Torrents from Cerebral Vortex as well as hatchet and bleed dmg. Even rogue has good potential as a tank with the ability to swap, using chakrams, discordance orb over wizard, etc.
A powerful damaging wizard, warrior and rogue are all indeed possible. same with damage reductions and the skills you want to use.