Ladies and gentlemen, prepare to have your minds blown......
Why not make bard a support bow healer and ranger the dps branch. Making bard more support than healing and songs with regen/heals. In terms of healing it would probably be the weakest, but in terms of support it would be the strongest.
Other mind blown ideas:
Make marauder branch. Heavy hammer user into a tank and make war a dps. Have pug branch into mnk as dps and wrestlers as tanks. Have mnk instead of "fist of" moves why not make them triple stance dance with moves particular to each stance. Have gladiators branch into tanks being Pld and Red mages into dps. Have rogues/ drg branch into 2 dps each. Nin would be a single sword so the other branch would be dual swordsmen. Lancers can turn into drg and Holy lancermen?Have conj branch into 2 healers. Whm and bishop. Leave astro, drk, and mch but add samurai as an extra job. these will be the unique of each healer, tank, melee, ranged.

Wanna a cigarette?