This suggestion would certainly work in making the mage equips more viable and more widely used, though I fear it would only help lukless builds since they can now get even more INT without much funding. The equips can also give some LUK for sure, but not enough to equip a high level weapon, and with the existence of maple weapons the benefit is just too great to not go lukless.
I like this suggestion, it's simple and removes the MP imbalance between the two builds, while not adding or removing any m.att.