Or they could do what was suggested in one thread and make it so you can't equip the job unless you learn the skills needed for it similar to how FFTA does it.

IE To Equip Black Mage as a Job you have to have at minimum Fire, Aero, Earth, Water, Ice, Lightning, Poison and Bio.

Just make the job system not unlock till level 20 so most basic jobs would be unlocked by the time you get there anyway.