Its not about seeing the weapon being use small hints alone proved they were going to have to do it since alot of people who would play this game has played atleast 1 other final fantasy with jobs like dancer so small little hints like that proves it.
as for raubhuan and griffon 1st He duel wields scimmys basicly a blue mage trait in some ffs second his nick name Bull of the east again basicly blue mage hint ... Griffon Saugan blade Lions etc all of their abilitys have a beast/monster name and has mele abilitys so ya basicly both are blue mages lol