In the FF games, honestly no. not when they were actual classes anyway, they always just were instead of 'jack of all trades' just 'characters who try to do a lot but suck.'
but other games got it right. symphonia's a good example of this. generally when they're done right they're just awesome at both (yes you *could* be better in either field but they do more than enough to fulfill the role), or when they're done wrong they just plain suck. rarely do you have a case of 'in the middle' but that game was one of 'em. though the end result still gave a pretty awesome one to play as. SMT also can be very good at this, with Digital Devil Saga being another nod as Gale, while not as good as anyone else in any category, was just so balanced that he fit your anything role, and did great at it. though in a series where versitility is a necessity, i suppose jack of all trades is in the awesome level.
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The King Wang.
Listen up Urinal Cake. I already have something that tells me if I'm too drunk when I pee on it: My friends. - Colbert.