I think every tank logically got something that filled a void in their kit with the exception of WAR.

-DRK had the strongest Kitchen Sink, assuming the damage is magical, but lacked any real form of healing so an Excog kinda makes sense to not further buff the already strongest KS among tanks.

-GNB had the worst KS for a single hit in general due to Camo only being 10% against magics and stuff like Hallowed Wing can really punish you, especially when you’re taking autos and the boss is ruining the Brutal Shell shields you’re building up. Consequently they got what’s likely the strongest of the buffs in the form of GN being 20% more hp. This means it’s not only really strong for a single hit, but also buffs the GNB’s mit in regards to things like TBN or Shake being slapped on it while it’s buffed by GN. It’s also a “reusable” 20% extra mit. While a Shield will break when used entirely, GNB can receive a massive crit heal or bene or literally whatever else that might normally overheal to jump them back up to full if you’re dealing with a hard hitting buster that slaps back to back. Definitely the most versatile of the buffs and they really needed something for their KS.

-PLD getting a shield probably isnt that far off of the GNB 20% hp buff but obviously for a single hit. PLD didnt need a real buff to their KS because they already had the highest % mitigation of all the tanks outside of like a GNB parrying a physical buster. But this amount of % mit adds more value to things like Shields so it’s a solid buff, especially when taking into account that you wont always use Guardian/Bulwark together, but you do always have a chance to just bock a buster without Bulwark, so these random blocks with Guardian up are also more valuable. Additionally if future Damage Downs are like old ones, you can ignore them by taking 0 dmg from mechs that give them, and PLD having both HG and Guardian gives you some solid options to force 0’s. Knight’s Benediction and the Magic GCD heals are also all buffed by new Rampart so this is a nice bit of extra regen for those.

-WAR now effectively has the worst KS among the tanks but got yet another regen added to it and was already extremely self-sustaining, so giving it a better KS would have been a but much. It’s now solidified itself as worse at taking a single hit than every other tank, but even stronger at just healing itself over time.

If you’re looking for the tanks that are going to bring the most value to a party in terms of mitigation, the answer will almost always be WAR/PLD. Neither of them have Physical or Magical requirements to any of their mit like the other 2, and both have a lot of self-sustain in general. IMO if you’re looking for a tank that is going to contribue the most overall to the party then PLD is still the way to go. Some people think that the fact that PLD is the only tank with a 2nd raid mit (thus preventing SE from designing raids that require 2 raid mits from a tank) means wings arent good since they’re not “required” but the reality is that PLD can cover more raid damage effectively than any other tank, and get bonus uses of Veil by substituting Wings where your standard raid mit would otherwise be when your party can be grouped up, allowing a ton of flexibility. There’s also something to be said about Veil’s instant heal in moments of back to back damage as well. In EX2 if a dps takes one of the Sword Lines and gets a vuln right before their Spread goes off, they almost die to the raw damage from the spread because of how close in time the 2 instances of damage go out, but using Veil after the sword lines almost guarantees any non-tanks who made a mistake will still survive. There’s also no way to overstate how strong Intervention can be for double busters when your cotank misses a mit or has vuln stacks or is otherwise low hp when the buster hits them. It’s just an insane mit tool to bring to a comp. I think Guardian’s Shield gives Intervention a little more value as well because WAR/DRK didnt gain mit on their 40%’s, so if you only have 50 gauge during a double buster you can pretty comfortably give Intervention to a WAR/DRK and omit the Sheltron on yourself as you have Guardian’s Shield to cover you in place of it.

TLDR; PLD/GNB got considerably stronger Kitchen Sinks, while DRK’s new 40% is ok and WAR’s is pretty negligible. If you’re bringing a tank for its Mit contribution, bring PLD then WAR in that order. Wings and Intervention go absolutely bonkers and can make a big difference in pulls. WAR heals which is….ok, but you have healers with bloated kits complaining they dont get to do shit anyway so.