A new tank stance to fit Dark Knight better

[Reynhart]

Unfortunately the bolded part is where it falls apart. If you have an attack that's going to do 25k damage in the final Alex Raid and both PLD and DRK are hovering around 22k with the equally geared WAR at 26,400 due to Defiance. The only one that is going to die is the DRK. It'll hit the PLD for 20k damage allowing him to survive. It'll hit the WAR for 25k of his 26.5k HP allowing him to survive. It'll hit the DRK for 25k of his 22k HP so the retaliation auto-heal affect would never be applied, he would not survive.

Sorry, but if a hit can do more than you max HP before mitigation, you'll pop a mitigation cooldown anyway, and you'll also probably have Stoneskin, Adloquium and Sacred Soil.
Just look at the actual coil, no tank will stay there just eating the buster without anything.

It's like saying that Shield Oath is bad if you have a Pampa boss with "25k needles" on a PLD with 22k HP and a WAR with 26400.

[Dement]

Sorry, but if a hit can do more than you max HP before mitigation, you'll pop a mitigation cooldown anyway, and you'll also probably have Stoneskin, Adloquium and Sacred Soil.
Just look at the actual coil, no tank will stay there just eating the buster without anything.

It's like saying that Shield Oath is garbage if you have a Pampa boss with "25k needles" on a PLD with 22k HP and a WAR with 26400.

Your right, everyone will try to mitigate it but in an actual fight things don't always go as planned and this was just a simple scenario to highlight the problem. In progression Death Sentence killed plenty of people, Ravens Beak killed plenty of people, Bahamuts claw killed plenty of people and Flatten killed plenty of people, all one shotted against PLDs and WARs, the DRK would be at an immediate disadvantage because it's reduction is tail end..