So even though anyone can theoretically do anything in games like FFVII, X, XII and XIII, most characters are still built a certain way that it's obvious what they were intended to be.
Like, I recall there was an article on here once about how sexist FF was for only having ladies b e White Mages. But for all practical purposes, Hope is the White Mage of XIII.
Meanwhile, Sazh would be the Red Mage with thoroughly middling stats and abilities.
Fang is obvious Dragoon with really high HP and Str.
Vanille is Black Mage.
Snow isa Monk. uses Fists and has the highest HP in game.
I'm not sure what Light is.
And I'm not sure about the other games. I was just giving some examples to start off with. What classes would you say the various characters fit?