To be honest, I don't think that your - quite often brought up - ideas of a 'Noctis Job' are that likely. Not regarding the fact that Noctis as a main character has a special spot and his personal lore for his powers which can't just be projected into FF XIV, there are other reasons. Namely, most obs being avaiable from a certain level and installed expansion only, not from MSQ progress. Your job would be quite the spoiler or just not making any sense for those not that far in the MSQ. (Yes, Heavensward did require a certain MSQ progress for the new jobs, but they admitted it was a stupid thing they don't want to do again).

Leave the armiger and that in their own game with FF XIV doing its thing.