It's such a terrible fight. One of the only ones that's so unfair though.
I just did that fight a month or two back, and I already have forgotten what I did. FFT is so open with the jobs and abilities that strategy advice doesn't necessarily work so well anyways, though. I know I went back and grinded for a few days, but I can't remember my final setup. But really, the most important thing is to just grind a buy. Some sort of speed+ is useful, and I always go in with most everyone being able to revive (Throw Item set if using Item for this, so AoEs don't wreck you so fast). I avoid charge-up abilities/spells. I think I favored dragoon for jump (keeping distance and avoiding a lot of damage) and monk (revive, chakra, and the ranged abilities, not to mention monks do good damage, at least at that stage of the game).
My setup was probably dragoon, monk, monk, chemist, and white mage. Not that this setup is necessary to win, of course.