Hutch333

... Which is a nice strategy against mooks in random maps. Of course it sucks against endgame bosses, but really, who in possession of their mental faculties would ever use a Thief against an endgame boss? I mean, outside of stealing the boss' equipment?

...Which is about the only thing I ever used a thief for.

Yeah, but you do need to gain some EXP for her. Level difference does impact the chances of succesfully stealing... Meaning she needs to do something in non-boss battles, be it inflict status, cast buffs or land the finishing blow on enemies (or take part in team attacks) in order to gain EXP...