CNJ is one of those classes that cannot branch outside of something healer-related, due to more than half its skills (10/18) being healing or support spells and skills, unlike ACN which had only 4 out of 18 skills being heals or support abilities. It will thus be under-powered or over-powered as a DPS or tank; it's almost impossible to balance to make it function as part of another trinity. Basically, any DPS or tank that can self-heal as it can with a CNJ's toolkit should not even be thought about. You can say to lock Cleric Stance so they can't heal, but that renders FIVE abilities utterly useless then. ASTs were already feeling the lockout with 5 semi-useless abilities at the beginning of 3.0 (Nocturnal Sect, Celestial Opposition, Collective Unconscious, Stella, Lightspeed); having 5 utterly useless abilities will either push the new job completely out of the raid scene OR make it introduce overly powered job abilities to make up for that uselessness.