oh no, DRK wasn't bent or anything, if DRK could wield BLM's staff, he would deal same amount of dmg from unmend, as BLM with 150 potency attacks (Scathe?).
Spells for each job are scaled with their primal statistics. BLM > INT, DRK > STR&VIT. That's why 150 spell damage (not spell power) is same to physical dmg dealt of 150.

I start to think, that despite the fact, those are magical scaling skills, they are actually dealing physical damage.
Since i still have no idea what "unaspected" is supposed to be.
That would explain, why Unmend and Low Blows deal same dmg, always, to all enemy types.

Unaspeted type as magical scaling spells, dealing Physical dmg. Sounds like a good SE move.