There are a lot of issues with the system as is. For instance, people very much expect a sword wielding DPS, but what are they supposed to do with abilities like flash and provoke? Nearly everything would have to be augmented to make any sense and at that point you're holding onto the system for the sake of it rather than because it makes any sense at all. There's also the very limited number of skills that jobs offer to really differentiate them from their class. Of the 5 skills, many jobs don't even use them all regularly. As others have said, they seem to be there to fill a quota.

While I don't have any problems with the armoury system as it currently is, it's not actually flexible in the way it seems like it was designed to be. Future classes will fit in just fine for a while, but jobs are more problematic. Even classes will be stymied by the 1:1 weapon to class ratio, resulting in future classes potentially using very odd weapons, or just arbitrarily defining certain weapons as belonging to one class and not the other (sort of like we see with WHM and BLM weaponry). While I like what they were trying to do, I feel like the best course might be an overhaul.