Aren't some of the other Limit Breaks from FFVII as well?
At first I thought it was weird that DRG got Omnislash, after all it's using a lance and not a sword normally..
But after some thinking..it makes sense. It's an aerical attack, involves lot of jumping around, etc.
There is no job more fitting to that than the dragoon.

Still...kind of weird to see a sword on a lance-using class.