Hmm... I think if they made a double ended weapon, that would be distinct enough an identity that you could have double axes, double swords and a double ended sort of spear (think Serge's Swallow weapon from Chrono Cross) without worrying about straying from a design standpoint.
That said, I'd be interested in gear choice. They'd probably prefer to avoid adding another gear type and diluting the drop tables further than just adding new weapons, so would you say they all get scouting gear and damage off Dex, or would say Green mage be in mage gear and have it's damage proc off Int?