The question is, does every job have to be unique? Is it not enough to just have different flavors of the same idea so each player can pick the one they like? You could have to extremely similar classes but by tweaking the animations and overall look of the jobs you can make two completely different flavors. Player A may prefer the one that casts fire spells and wields a mace while Player B may prefer the other flavor with ice spells and an axe.