Historic points aside, my recollection matches yours except I think warrior use to have an even higher penalty at one point, I agree, outside of prog, tank stance for mitigation isn’t an often relied on strategy anyway, but I think this points more so to making it oGCD since what it is used for is picking things up when your cotank dies, or just adds that spawn. Grit costing 1 dark arts is enough for me to try and not use it as mitigation at all, Shield Oath and Sword Oath costing a total of 1 requiscats is enough to make me try to avoid using shield oath as mitigation. The GCD cost is just even more deterrent which is unnecessary since the mp cost was enough to make me go “woo lets not get crazy, tank stance?”. I’m not even going to mention the third deterrent, this much negative for an extra rampart and my assumption is devs don’t want me to use this skill.
I know I’m addressing things out of order, but now that we agree that popping into tank stance to mitigate and then switch off is an uncommon practice I would like to point out the major benefit here we aren’t mentioning.
Switching deliverance defiance deliverance does NOT lower your HP, this has a major implication, you can erase a higher % of an attack than paladin and dark knight if you play your cards right because your mitigation is based on your max hp, not DM on the attack itself. And heres the kicker, its not hard to do it just means you might need to talk to your healers.
Since the common practice is to go dps stance, tank stance, dps stance lets take a look at the whole sequence:
My tank has 66k HP. Lets take a tank buster for 50k
On paladin and dark knight I will mitigate that by 20%, leaving me with 26k hp, I drop my tank stance, lowering my defense, and have 26k hp out of 66k max.
On warrior, I am going to need to give up an equilibrium to heal myself (or plan with my healers to heal me to max hp beforehand but one has to wonder what else we are using equilibirum on). Prebuster my HP should be at 82.5k, I take the buster reducing me to 32.5k hp, I drop tank stance, and have 32.5 hp out of 66k max.
In the warrior sequence you mitigated 16.5k damage by cycling in tank stance and working with healers, for dark knight and paladin you mitigated 10k.
You can check the numbers for a variety of tank buster damage, but provided the damage is not above your max HP, Warrior actually has higher survivability by manipulating their tank stance and using their defiance hp as a shield. Again, maybe it doesn’t have an immediate benefit and needs some planning, but like the rest of the warrior kit, if you work it right your weakness becomes a strength.
Here is the math showing to mitigate an equal amount on paladin and dark knight how much damage you need to get hit for to match the warrior max HP strategy:
starting from the relationship: Direct mitigation*Damage = HP Shield strength
we can rearrange the equation to give: damage taken = HP Shield strength/direct mitigation = .25*HP/.2 = 1.25*HP = warrior tank stance.
To show the range where the HP Shield is more effective than damage mitigation solve the inequality:
Direct Mitigation*Damage < HP shield
Solving: Damage < HP shield/direct mitigation = .25*HP/.2 = 1.25*HP = warrior tank stance.
As tank buster damage increases towards max HP of the warrior in defiance (the 25% bonus), the two styles of mitigation are mitigating more and more of the same. There is a tipping point, above your max HP (in tank stance) warrior's mitigate less and paladin and dark knight begin mitigating more, in this range we begin pairing other mitigation anyway to try and get the mitigated damage down below our max hp anyway. And of course, that is a moving target as well, you also have thrill of battle which further increases your base max HP and allows for more HP shielding (up to 50% of deliverance HP when paired with tank stance), but I don't want to make this post any more complicated than it is already. The point is, this idea of no "immediate benefit" means others must pay a huge price while warrior gets numerous beneficial abilities to counter its tank stance "weakness" is very dated.