Wait, wait, wait. What if we're looking at this wrong?
Instead of "WAR multi-tank, PLD single tank", let's look at this another way it could be done.


What if a PLD was so self-sufficient, you didn't NEED a WHM to look after it? What if the damage it took, and it's abilities and cures, were enough to keep ITSELF alive in any situation?

I'm being serious, as this could be balanced properly.

WAR excels and dealing damage while tanking, right? So it's ideal when you don't mind bringing a spare mage, or your only WHM doesn't mind looking after the tank and the party.

Now why can't a PLD excel at taking minimal damage and keeping itself alive so you can either A) Replace a mage with a frontline class or B) That single WHM can focus exclusively on the party unless you have a major "Oh shit" moment. The drawback would of course be that PLD deals absolutely crap for damage.

If it was implemented like this, instead of an answer to the WAR, then I could see two very distinct differences in tanking.

WAR - Damage tank that requires mage attention.
PLD - Mitigation tank that doesn't need mage support, but deals minimal damage.

How to do this? Well, I'm no game designer so I can't say exactly if these suggestions would break the job, but it's better to think of ideas than to sit idly by.

Aegis Boon - Make this a 20 second buff. Instead of automatically blocking the next physical hit, it activates during a shield block. Damage taken from the attack is cut in half instead of nullified and you and party members in range restore HP equal to half the blocked damage. Stack with Divine Veil for maximum effect.

Bring back "Obsess"- This ability increased your defense against one target while reducing it against another.

Make Defense worth something - Pretty self explanatory. Sure, WAR can wear the same stuff PLD can for the most part, but PLD should have a naturally higher defense.

Change one more part of Divine Veil - Instead of Regen, make it so that when a PLD is cured, it heals nearby allies as well. Make PLD a pulsing beacon of healing.

Give PLD Defender. - I still don't understand why we don't get this. Do you WARs even use it? >.>

Allow us to parry with our sword, even if we have a shield equipped. - Give us some defensive swordplay! An ability like "Riposte", a reaction ability usable only after parrying an attack, that deals light damage and combo's with Spirit's Within.

I'm really tired. I'm sorry if some of these sound gamebreaking or unreasonable, but if we just overboost PLD's survivability and leave it's damage at the low end, then PLD makes huge leaps in practicality and WAR doesn't need to be nerfed.