I end up mastering/almost mastering every job for everyone since Protip: Your Jobless Class get's a stats bonus for mastering the best jobs w/ the best stats, for example, You master the Ninja, you get Ninja speed (as well as inherited Dual Wield) You master the Monk, you get the Monk's strength (as well as inherited Counter).

If I don't do that, I usually give Bartz physical jobs, Faris speed jobs, Galuf physical w/ a few magics in preparation for later in the game, & Lenna magic. When I get Krile, I give her magic jobs.

If you're going to give Bartz jobs of his own, I'd recommend Ninja, Mystic Knight, Monk, Knight, & Ranger. Ninja for speed & Dual Wield, Mystic Knight for the Magic Swords, Monk for strength & counter, Ranger for !RapidFire.