Tank DPS Ranking prediction.

[Reynhart]

Their survivability is just as good as Paladin, their Parry Buff is FAR superior than Sheltron.

Ok, you'll probably ignore that post, but whatever, here's where you're wrong.

Mitigation skills need to be compared either by cooldown or duration. Like you said yourself :

FFXIV tanking rotations revolved around big, predictable, mitigatable hits.

So, basically, duration is not a big problem there.

So, cooldown ? Raw Intuition...90s, Sheltron...30s. Is it basic enough math ?
Well, in fact, Sheltron is not the PLD equivalent of Raw Intuition. It's the equivalent of Inner Beast, as they're both "pop it at will to reduce one hit".

Bulwark is the equivalent of WAR Raw Intuition. So, is Raw Intuition better ? Yes, on paper, it is. Shorter cooldown, and more reliable. During fights ? Well, it stills have shorter cooldown, but in the whole rotation, both tank can have their coolwdowns when they're needed. As for the "reliable" part, Raw Intuition is also better, but the difference is slight at best, since Bulwark is added upon the natural blocking rate, which is already decent, depending on the shield.

For the mitigation part, although, recent Parry test puts it at a flat 20%, exactly like Inner Beast, whereas block scales with shield and level, but stays consistenly higher than that.

So, now that Inner Beast and Raw Intuition got their equivalent, what do we have ?
Defiance for Shield Oath : So close that it doesn't really matter.
Vengeance for Rampart and/or Sentinel. Vengeance is exactly mid-way through both with better mitigation but longer cooldwon than Rampart and lesser mitigation but shorter cooldown than Sentinel.
For once, let's look at "average" mitigation.
Vengeance : (30/180)*30% is 3.75%
Rampart : (20/90)*20% is 4.44%
So, on average, Rempart is better.

Then, you have Thrill Of Battle. It gives you 20% more HP whereas Sentinel reduces damage by 40%. In terms of eHP, thats 120% against 166% (Since they both have the same eHP when comparing Defiance and Shield Oath)

As for Halloweg Ground vs Holmgang : Hallowed Ground negates all incoming damage, meaning that healers don't need to do anything for the duration and doesn't stress them once the cooldown ends. Whereas Holmgang makes you die in one hit once its down.
Holmgang as a much shorter cooldown, but, for the moment, there's no fight that "requires" several Hallowed Ground of Holmgang to makes it really matter.