[suggestion] Remove charisma from champions
The only effect of charisma is according to my knowledge to make hired champions cheaper. This effect should of course only depend on the charisma of the souvereign (remember you can hire champions as soon as they enter your territory).
Therefore offering the possibilty to increase the charisma of one of your champions is simply a trap to new players and to the ai.
Alternatively you could make charisma actually usefull, e.g. by creating diplomatic infuence or improving some things within a city whenruled by a champion of high charisma. E.g., +0.1 presige per charisma of the champion or something along these lines.