You know what, I'll say something that's on topic in a minute but I can't let a statement like this slide. I've seen far too many people say they don't like the game because it can play itself and it is without a doubt the stupidest thing I've ever heard. If you don't like the game playing itself then don't let it. It doesn't force you. I gave my characters enough gambits to hopefully keep themselves alive if things started going horribly wrong and I was to pre-occupied with one character to cast a cure spell with another. Beyond being able to keep themselves alive on their own for the most part (and even then they'd get themselves killed against some of the tougher bosses), I did everything else myself. Considering you did all but 4 hunts and with it a probably very overpowered party for the final boss, I have no sympathy for anyone who complains because their party beat the final boss with no input. What the hell did you expect would happen when you set up an over powered party with effective gambits and cut them loose? If you don't like it, then don't use Gambits.
Anyway, rant aside, I did keep my characters largely to specific classes, though I wasn't as specific since I only used three characters. I basically gave Balthier Green and Time Magic, Fran got White and Black Magic, and Vaan got Technicks for the most part. Weapons and armour were mostly in line with what they start out with except for the few occasional I had to cross over to a different type to get the next level of their usual weapons or armour. I think I went mostly with lighter armour and guns and crossbows for Balthier, light/mystic armour and bows for Fran, and light/heavy armour and swords/axes with Vaan.
I like the classes you came up with though. If I were to play through again with all six characters I would probably choose something similar to that.