What if FFIV had a job class system?

It was always interesting that FFIV decided to stick to pre-establish roles for each character, but what if FFIV had decided to let you change everyone's job class instead? To make this simpler, you can only use job roles from FFIV and below. How much do you feel this would change the game, would it be for the better o do you feel IV needs established job roles instead?

Cecil would never become a Paladin, because the Dark Knight class is incredibly broken. I'd just leave him a Dark Knight and spam Darkness to victory.

I would make everyone a Dragoon.

I think tinkering around with a job class would easily break the game from the get go, so the whole game would have to be rebalanced and retooled so you don't plow over everything in sight after gaining a few perks from whatever jobs the characters have. It would be fun to play for people like me who has played the game countless times thought multiple versions.

Inf FF4 the idea of job class is really intertwined with character. In the later series entries everyone is more generic, but it FF4 everything about each character bleeds their job class.

Adding a little more customization would make sense though. Making Kain into a mage makes no sense, but having him have a little bit of branching into other physical classes could be something I could see.

Yeah, running this game with Job Classes would completely kill a portion of it's Charm.

Rydia is a summoner because she's a smurfing natural born summoner by birth.

Cecil is a Paladin because he repented for his dark ways and rose above his past sins.

Ect. Ect.