License board. Actual customization is better than the illusion as Wolf Kanno said, and I had no trouble sticking to defined job classes throughout the entire game, right up until I beat it. In fact, I'd say it was downright easy to keep them to certain job classes. If I wanted a white mage, I'd give them white magic instead of black. Not rocket science, and not hard to do. It's also not as easily exploited later on in the game since leveling still plays a decent role in developing your characters, not just what abilities they have.