Okay, saying Vincent shouldn't exist is a little harsh. I like both of them

As for the topic.

Vincent: Mysterious, quiet loner with guilt issues but don't endanger someone in front of him. Personally, I think the gun suits him. Allowing him to stay away from the direct fray but still helping out.

Cid: Loud, foul-mouth, in-your-face type who wants to fly. A gun just wouldn't suit Cid very well. He needs to be in the middle of the action, not standing on the side lines, sniping random things.