The Classes in XIV are generic because all they are supposed to be is your weapon. Gladiator = Sword, Pugilist = Knuckles, Marauder = Axe, Archer = Bows, Lancer = Lance, Conjurer = Circle AOE, Thaumaturge = Cone AOE.
You learn skills by using weapons then mix and match the skills together to make up your own Character not a class or job.
They already said they will be implementing the Classic FF Jobs to instill a sense of Role for players should they chose. And make it easy for other players to identify that "Hey that Gladiator is a Thief, not a Paladin."