I said the lancer / tank portion because someone mentioned lancer = tank (templar) with white mage sub. I was pointing out that people don't use cure too often on pld. (maybe if they have nothing better to do outside stoneskin)
Also you are right, you don't have to unify everything in terms of class = job. Realistically people are going to QQ either way if the class they play a job from doesn't get a secondary class anyways.