I hate using Marche, but I have him as a Ninja/Thief dual-weilding Auyver Red and Auyver Blue. Make sure you get Dual Wielding as soon as possible and I rarely used S-Abilities. One hit by him's strong enough to take out most characters.
I never changed around the jobs so much in this game cause i didn't think it was quit that fun. FFT was so much better. All i really cared about was the story in this game. So i say....Paladin!