A commonly cited problem this expansion is that every tank is just a homogenised re-skin of the others. It's a problem, but a necessary step that had to be taken. Prior to Shadowbringers, certain tank jobs were grandfathered in to advantages that made them mandatory. We've gotten rid of that. Now you have choice, but it's a boring one. But it's a step in the right direction. Now we can start looking at ways to make the tanks feel different, yet be capable of similar performance.
The next step should be to give each job unique ways of accomplishing the same tasks. Despite what anyone says, self-healing tanks are really fun, and they work (see Warcraft and Death Knights). Prior to this expansion, I had recommended that DRK be the defacto self-healing tank given their 27-year history of HP manipulation mechanics and abilities like Souleater and Abyssal Drain. It also would have made the most sense given the fact that Living Dead requires you to burst heal through a lot of damage. But for whatever reason, WAR has gone down this route, especially with the changes to NF. So if the devs, in their infinite wisdom, have decided that WAR needs to be far better at self-healing than any other tank, let them focus on that. There's really no point in giving the other three tanks equivalent abilities when they've already committed to this decision.
The issue of 'anticipating' incoming damage is simple enough. You just need two sets of abilities; one set that boosts your max HP temporarily, and a second set that gives you lots of self-healing. Let me give you an example. Let's say that Eye gave you a 'momentum' buff which increased your max HP (without healing you) and your attack speed. Both then decayed over time on a per second basis until you reapplied it. You might have some abilities that gave you a sustained rise in HP cap without healing (ToB, Raw Intuition) with others that just healed you back up (Nascent Flash, Equilibrium). Now you have a lifestealing tank that can try to boost their HP levels to anticipate incoming damage. And give them Living Dead, because let's face it, Holmgang literally means "dual to the death", and if you're going to have the shortest recast invuln with the highest offensive burst, you should be fighting for your life to survive.
DRK, by contrast, could very easily focus on revenge mechanics. TBN is all about this. Take enough damage on your bubble shield, get a free counter attack. Do you know what people miss the most about Reprisal? It's not the fact that it's damage down. It's the fact that you proc it defensively and then get to counterattack stab your opponent. What we need are barrier shields, counter attack procs when said shields pop, and lots of interplay between blood and MP. Let it feel like a completely different tank. One based around vengeance. The end should be the same, but the means should always be different.