I'm not saying its unworkable but honestly it's biggest damage mitigating skills for the physical side of things is it's evasion and parrying if these actually were worth a damn I wouldn't mind its physical defense. Essentially the two skills i mentioned are meant to act as a equivalent to a PLD's shield ( a form of damage mitigation), except anything worth fighting will laugh at the evasion and parrying because they are so useless when fighting anything that is of much higher level than you.
So granted I understand as far as melee jobs are concerned its DEF isnt too bad but when it's supposed to be supplemented by things that don't work it just exacerbates the issue to the point that on the whole it leaves a lot to be desired.