Personally I want a system that acts like the Job/Subjob system where a Job Title acts as the Job, and the Weapon Class/Discipline acts as the Subjob.
Carpe's system is the best explanation of this system. The Job Title Defines the Role, the Weapon Class/Discipline defines how the user performs that role.
I also do not believe in any system that limits a Specific Job to a specific Weapon. Paladin shouldn't be limited to Sword and Shield by the game, only the player. If someone choses to try playing Paladin with a Lance or Axe they should be allowed too.