As has been said, that's actually a PGL wielding katars I'm sorry (the image can also be found here: http://finalfantasy.wikia.com/wiki/Pugilist ).

Also I seem to remember hearing that Yoshi is planning on removing daggers/knives from GLA/PLD and giving them to a new rouge/thief type class, but I haven't heard anything more about that, so take that with a grain of salt.