Ok let's look at the Final Fantasy games and it's "Job systems".

FFI: set jobs/roles but you can choose how many of every job you want at ebginning
FFII: no jobs but every character can do what he wants
FFIII: free job system
FFIV: set roles/jobs
FFV: free job system
FFVI: set roles but magic is learned through espers which you can equip as you want
FFVII: limit breaks and freely usable materia system
FFVIII: limite breaks and freely switchable GFs and Magic system
FFIX: set/jobs roles
FFX: freely usable Spheregrid + Overdrives which you can consider a bit job like
FFXI: free job system
FFXII: license board

As we see only FFIV and FFIX has really set roles through the whole game. In FFI you can decide at the begining but it's set after that.
The rest has either a completly free system or set system for character + a free system.