Thats good for you because you could like put protect and junk on Fran and they would be wasting their attacks on a Protected character.
Of course I thought of this but I wont go for it. I already have her as my black mage it's to far in the game now to look back, besides i have solid snake (basch) and vaan to do all my front line attacks

and no I don't lead the way into battle with my mages my main character throughout the entire game has been Vaan

I can't see that it could be gambits because then it would mean every monster in the game share the same gambit if it was there should be some variation in the battles and believe me when i say everytime I mean Everytime.

The only possibility left is the hate system you mentioned, though I will try changing her stats a bit