The math between Defiance and Shield Oath comes out with both basically doing the same thing. The 20% reduced damage from SO creates nearly the same effective HP gain as the 25% increased HP on Defiance.
So, in that sense, WAR and PLD are spot on The issue comes with cooldowns. WAR gains a native 15% increase to healing with 5 stacks of Wrath, and the heal gained from sitting on those stacks is always going to be better than the heal gained from Inner Beast, unless you have Infuriate available. At that point, feel free to IB, because you can pop back into 5 stacks instantly.
This reduces IB to what is basically a 60s CD skill. To further complicate the issue, ensuring maximum IB gain requires four things to occur;
Berserk needs to be up.
Maim has to be active.
The enemy needs to have Storm's Eye debuff active.
Inner Beast needs to crit.
Taking all of that with a relic weapon will get you a heal of ~2400 or so on Titan. If none if that happens, then IB will heal for 800-900, which isn't even half of a Rock Buster.
So when Titan Final phase comes along, and he's RBin'g for 1800ish, then normal attacking for another 600, followed by a 4700 Mountain Buster, all in the span of about 6 seconds, you're looking at over 7k damage to soak. With relic, two pieces of AF2, and the rest darklight (and hoplite ring) I've got 7495 health in Defiance with party vit buff. The *only* reliable cooldowns I can use to deal with that are Thrill of Battle and Foresight. ToB works fine, assuming I'm at max HP when I use it, and Foresight does what it advertises, which translates to a ~5% damage decrease while it's up (but only for physical attacks). And that's it. And one of those (Foresight) may as well be a placebo effect for how well it works!
What really determines whether or not I live or die on Titan has almost nothing to do with what I, as a WAR, do. It is entirely on the backs of our healers and dps. The dps need to not take any damage ideally, except from unavoidable sources. The healers need to know that, following a Landslide, the WAR tank needs to be full, with Adloquim, Succor an Stoneskin on him. Titan needs to be debuffed with Virus or Rain of Death or Eye for an Eye (or ideally all three) so that when the attack comes his damage is cut in half, if not more.
Meanwhile, a PLD has a LOT they can do. Rampart just flat lowers the damage they take. Sentinel too. They can Blind Titan and up the chances of a miss happening (yes, WAR has Featherfoot, but the cooldown on FF is so long you'll use it once every 3 MB's, while Flash Blind can be up every time). They can also pop Foresight, which has a slightly stronger effect on PLD due to higher defense. And if all of this fails, and they're sitting at 1k HP right as the final hit is about to come in, they can hit Hallowed Ground and just /laugh in Titan's face.
Which is fine. That's what PLD's do, it's their job. But WAR lacks that. Up until Titan, it's not an issue. Past Titan, it becomes an issue. Healers have to work that much harder to get a WAR tank to work, simply because WAR lacks the same ability to "take care" of themselves compared to a PLD. Inner Beast is great, but it's not preventative, it's reactive. We need to survive to use it in order for the heal to matter, and the fact that it's on the GCD further complicates things.
Overall, WAR isn't in a bad place, but it needs some tweaks. Being a reactive tank means you count on your healers to always be babysitting your HP bar, because you need to survive the big hit to use your big mitigation ability. Lots of ideas have been floated, such as making IB provide a shield for excess HP healer, so that you can use it at full hp, get a crit for 2500 and get a shield for that much. What it will end up being, I don't know, but WAR needs something.
The thing about me is that apparently it's very hard to tell when I'm drunk. So I feel like I'm walking sideways on a UFO and everyone else sees me doing the robot like a pro.
i have bathed in the blood of many. my life was spent well.
feral druids do it on all fours.
The One True Prophet of Tonkism.