Honestly the worst part of Bulwark is its Recast time. All tanks have cooldowns that are a little on the dicey side and not intended for mitigating TBs (if you use Bulwark on a TB and nothing else... yeah.) but when used properly smooth out incoming damage and provide spike mitigation. But none of them have a fucking 3 minute recast.

That having been said, I don't think PLD needs defensive buffs. Its more or less fine where it is on mitigation if you ask me.