I sort of wish players could only choose one job.

[Charismatic]

Really? Their limit breaks would suggest otherwise. Each game has their own variation of what characters are capable of and how jobs work.

Quistis was a Blue Mage
Zell was a Monk
Selphie was a Corsair
Irvine was Ranger
Rinoa was a Sorceress/Black Mage (Unique to ff8 because that's essentially what the whole game is about.)

We can pass it off as mere coincidence that each one of these characters just so happen to posses abilities that correlate with a job, or we can acknowledge it for what is.

You're being silly. Limit breaks being the sole determination of someone's "job" which is generally their role in the party lest we forget... it doesn't hold up under scrutiny.
Just imagine if I have my Irvine set to do nothing but heal... simply because he has shot limit breaks you'd call him a Ranger rather than a White Mage though his role is that of a White Mage (and malleable at that)?

Quite silly.