No. I use a knight, bm, monk, and thief at first. Then, when they get better stuff, I upgrade their jobs to compliment their base class. So for example, Bartz is a knight, so he gets upgrade to stuff like Samurai. Ferris gets stuff like ninja, archer. Galuf gets berserker, trainer. Lenna gets red mage, summoner, shit like that.
Exploits are boring unless they make the game harder.
Just like with any rpg, I give each character a defined role, usually given off by the story or their character background, and I keep that role throughout the whole game. So in my game, Bartz isn't going to learn magic. He's no mage, he's a fighter. Faris ain't no mage or a warrior she's a pirate, a thief. Galuf is this amnesiac old man who's got a mean fist, so I give him any and every class which is nature or bare fist-based since he's got balls and he rocks. Since what's her face is his granddaughter, I give her a similar style, mostly because I'm lazy and don't want to break up my style. Lenna's a princess, and she's quite fragile. So I give her all magic skills. She's my only mage in the game.
I do this with every single rpg I play. Even in games like FF7 and FF12 which have customization systems that call for the characters to be similar.
THe job system in FF5 is so fun because it gives you so many options. Mastering a job and giving those skills to the character while he's using another job, complimenting his current class is fun as fuck. Every time.
