Create a FFT (tactics/advance) system XD
Can use jobs to unlock jobs. Certain jobs may be considered advanced jobs that have extra restrictions applied to them. (Also means weapons are not the job maker)
Can get around things like "How the hell do we make a blue mage without making a class dedicated to it that doesn't want to share any of its abilities with other classes" and can also do things like "Perhaps the bard should have an instrument and a bow..." (get around ability and item restrictions).
You can sort of do some of these things like making a class use two types of items but say you want to make a bow that both archer, samurai, bard, and ranger can use. The system support will start to become convoluted as rules come in place like "can be secondary weapon for samurai is main hand weapon for ranger, bard has secondary harp). Gladiator using a dagger x thief using a dagger x thief's base class using a dagger.
(However to separate classes from jobs in feeling (abilities/skills) in the current system.. good freaking luck)
Though I can see some people saying (perhaps you

) "I dont want to level a new job but rather "extend" the current class". Which is preference, I cant really argue about that.