The very name says it all Musket-eer they use guns/rifles stand in the back line and shoot. I'm not saying it could never happen but the Gunblade is quite a different weapon to a Musket and probbably Musketeer has about as much of a chance of weilding one as Gladiators do. They would really be wasting Squall Lionheart nostalgia by making a Gunblade Class/Job that stayed in the backlines.