I agree with everything except this. I think you are overestimating the balance of these skills, and you are not taking into account the disparity in their cooldowns and what that means for combat. Lets look at the skills in detail:
Hallowed Ground:
- God tier mitigation
- Lasts 10 seconds
- 7-minute cooldown. You get 1 of these per fight* (I have never had two).
Holmgang:
- Invulnerability at 1HP
- Lasts for 6 seconds
- Binds for 6 seconds
- 3-minute cooldown. You get 2 per fight, 3 in longer fights*.
Living Dead:
- You don't die from HP hitting 0
- Lasts for 10 seconds
- Needs a large heal or else you die
- 5-minute cooldown. You get 1 per fight, maybe 2 if used early*.
*based on a 9-12minute enrage timer
So lets break this down. For ease of analysis we will take hallowed ground out of the equation, it is the best skill with a massive cooldown, you get one per fight which means you have to plan around that fact. It is strong but not versatile in the slightest.
Comparing Holmgang and Living Dead we need to look at the drawbacks of the skills, namely the bind and the need for a heal: The question is, how detrimental is the bind and how detrimental is the heal? I would say the bind is not all that detrimental because it is rare for a tank buster to require movement at all, meaning that the bind is not a detriment at all, in fact, if SE ever puts in a scenario where an enemy can be bound to the partys benefit, then Holmgang is far far better than living dead in every way.
Oh, and to counter your pros about Living Dead, while it is true that you can abuse it, it does require coordination with the healer, and for them to save skills that could be used elsewhere (benediction is on a 3-minute cooldown, lustrate requires aetherflow).
This is all without mentioning that WARs superior self-healing directly affects the functionality of holmgang.
So we see above that the bind and the requirement for healing both have pros and cons, and are pretty balanced against each other. So why is it that holmgang has almost half the cooldown of living dead? Put into perspective above, in most cases DRKs will only get as many living deads as PLDs get hallowed grounds (a far superior skill), when WARs get two Holmgangs guaranteed with more option of a third than DRKs have option for a second Living Dead. I have seen this be relevant first hand on exdeath savage first phase, where WAR can cover the 1st and 3rd Thunder III, whereas parties with a DRK/PLD comp need to swap to cover their longer cooldowns.
So even here DRK loses out and I would say that your score should be +1 WAR/PLD, +0 DRK making your final DRK score a pitiful 3
Edit: A simple way to perfectly balance these skills is set living dead to a 4 minute cooldown, but until they do that DRK loses out.
How relevant is the movement 90% of the time?