exept the enhanced shaman is not really a melee magic dps... more a melee with a bit of magic. and wow is not know for have the best balance around.

other point the shaman enhancement use mail armor and dual wield for be viable. most of him "spell" are instant cast or limited into utility.
Wow systeme allows this sort of jobs to exit by creating different spe that give totally new spell depending of what you choose. that not the case in FF14.

and i will say it againt a jack of all trade is nice into a solo game.... in MMORPG it's horrible. if they can't offer the same stuff than jobs that can only do dps, heal,... no one will want them, but if they can do all... why bring the jobs that can only do one thing? since we don't have a systeme of specialization... this sort of jobs is not possible