Yes I do realize that but the actions' potency are kept the same. Think potency y as the multiplier for your damage x. Scaling damage is done by scaling the weapon damage which affects x already but if you're scaling the multiplier y as well, that results in very varying damage.
I have had no problem with aoe hate management on PLDs and the only content I haven't beaten is turn 5. Have done adds many times and never lost hate.
