Paladin doesn't have to use a Sword. It can use a Sword, A Polestaff, a Polearm, a Club, a Hammer. Even a Bow. Not to mention Shields.
Jobs shouldn't be seperated by Weapon. Weapon Classes are (which is why its the Armoury System its a Weapon Class System) The Job system just fits on top and lets you play as a Paladin as a Lancer, Gladiator, Pugilist what ever you want. What ever system they use shouldn't limit what Weapon Class a Job can use or vis versa.