Yoshi P talks about Warriors- from Producer Letter Live @ TGS

[Sargon]

so in the long run, WAR really only gets somewhere between 10-15% persistent mitigation. PLD always gets its 20%

Just a reminder, heal buff % cannot be simply compared to damage reduction.
100 -20% = 80

10 hits => 800dmg on PLD, 1000dmg on war
+15% on a 800hp heal = 920hp

To have those 1k hp healed back you need a permanent 25% heal buff.

[Kyzr]

Just a reminder, heal buff % cannot be simply compared to damage reduction.
100 -20% = 80

10 hits => 800dmg on PLD, 1000dmg on war
+15% on a 800hp heal = 920hp

To have those 1k hp healed back you need a permanent 25% heal buff.

^This.

Who cares if I have 25% more HP if it still takes 20% more mana and GCD to heal through the damage we're taking? Even if you have a BRD and the mana never becomes an issue, a healer still has to heal a WAR 20% more OFTEN than a PLD. There's no permanent +20% casting speed buff in the game, and even if there was, PLD would still be leaps and bounds ahead. Why? Because there's no way a WARs damage is better than 2x Healers doing damage instead of 20% more healing.

For a WAR to be better than PLD, they have to do more damage than the PLD plus the extra damage healers get to do when they have a PLD. There's no way that's the current state, nor should it ever be.

[Leiron]

saving characters

You're going under a different context.
If you have 25% more health, its roughly the same as having 25% mitigation.
If you have a 15% heal buff, its about the same as having a 20% damage mitigation on top of it.
This does assume, however, that the healer has enough mana and healing power to top you off.
Otherwise, if its a war of attrition, mitigation becomes better.
I genuinely think SE didn't consider healing power/mana, and also did not factor the rest of the mitigation that Paladin receives which gives it much more effective HP in the end.

So while Warrior has greater health, its total eHP is lesser.