Thing with paladin is that ACC gives it enmity. PLD gets a lot of it's enmity from certain skills, and missing that one skill can hurt a lot. However war itself gets their enmity from raw damage. This means that even if war has a high damage, the enmity bonus they get isn't that high. So while flat blade is like a x5 multiplier on enmity, wars have to go off damage so they need more enm +.

ACC is something all PLDs should want, and with the WAR relic not having any, they need to lose some sort of damage/mitigation/enm somewhere to be able to use that axe.