I think a lot of the "problems" with Paladin actually come from the game mechanics being faulty, not Paladin being a weak tank.

First off, time requirements on chests already encourages people to bring whatever makes the dungeon go faster, so you bring war. Second, we as players choose to ignore how monsters are "suppose" to be killed and just take the path of least resistance.

Ex: Coincounter
I'm sure most groups decided to just have WARs stack HP gear, and eat 100 tonnze. However, you're "supposed" to dodge that move, and are rewarded when doing so by having a stunned boss.

Ex: Chimera
SE most likely wanted us to fight this in the middle, incap it's body parts, and fight with at most 2 BLMs. With everything incapped, I'd bet 1 Whm and Holy Succor would be more than enough healing. We instead stand out of AoE range, use 5 BLMs and take a WAR tank for faster kills and a bigger HP pool as a safety net for when hit with TP moves.

Paladin -might- have more use if we did fights the way SE intended them to be fought, but there is literally no reason to follow their path. Sure, you can do 5 chest runs with a Paladin tank, but why would you add that additional stress to yourself/your group? As I said before, we as players look for the path of least resistance (even more so now, since messing up CC/AV runs means less chance at darklight), and that is something SE clearly did not prepare for when introducing Paladin and these new dungeons.

Paladin can either be buffed somehow, so it can act like a Warrior in these fights, or SE can make us do their content the way it was intended. I'd rather the latter honestly, class stacking and standing on a wall is pretty lame.