I decided to test this last night

Marauder+weathered axe+heavy swing (150 Potency)= 9-10 Damage
Gladiator+weathered sword+fast blade (150 Potency)= 6-7 Damage

Weapon skill damage seems to be clearly based of the auto-attack damage normalization is not a factor.

Warrior relic+1 is 52.75 auto-attack
Paladin relic+1 is 35.57 auto-attack

So assuming damage calculations for weapon skills use auto-attack damage and do not normalize the damage based on weapon speed as seems to be the case here, the potency calculations from the above post are not even a remotely correct representation of warrior and gladiator DPS.