So for a hack, I was thinking that !Lance (name aside) makes more sense as a Black Mage ability. Giving them a back-row damaging way of draining MP is classic, like "Rob Magic" from Dragon Quest. Also, !Lance being Magic based works better with magic characters.
For Dragoons, I'm thinking of giving them !OpenFire instead, as a decent back-row attack. Dragoons love the back row for jumping, but outside of jumping they're pretty weak. This will give them two options. I thought about giving them Long Ranger to reflect the Spear's longer reach, but the problem is it is too powerful a learned ability on other melee classes.