This doesn't solve the problem of PLD vs. WAR imbalance, lack of reward from tanking, clumsy emnity mechanics where you just have to sneeze hard enough at a mob to rip aggro off the tank, and the fact that dungeons are haphazardly designed to require 1 tank in one case, 2 tanks in another case, with no consistency.
People aren't tanks in FFXIV because I'm going to be honest, you're either playing EZmode PLD and bored to tears or you're playing original Halo Legendary difficulty WAR and it's literally impossible to be main tank once you reach a certain point in endgame. There's no in between, so people who actually like a challenge but who don't want to face mathematically impossible difficulty have nothing else to do but roll a DPS or healer class. The two tank classes don't have anything resembling rewarding play right now.
Did you know you can Flash at the right moment and blind Titan HM, negating the only thing that might even remotely threaten a PLD tanking him right now? It's possible to avoid Mountain Buster 100% with the right timing. So PLD literally can't be harmed by Titan HM. Meanwhile WAR gets killed so bad by Titan HM that most people who play WAR take him to Titan HM as a DPS and let a PLD tank him just to pass the fight and get their relic. That's how balanced PLD and WAR are right now. And neither are that much fun to play at endgame, one class is OP and boring and the other is dead meat and impossible.