To add some flavor to the game, some new titles could be included. Instead of just having three or more chancellors, something like this.

Each title can only be given to 1 knight.
Having specific titles may help increase role-playing or for diplomacy. For example a
king's champion might have a duel / show-fight to resolve a matter of honor with another kingdom's champion. With 2 protectors the
king's champion title would obviously be given to the strongest knight in the kingdom (prestige, respect etc)
The above table is an example. The titles, building requirements, costs and benefits can be changed to ensure balance.
At the moment you can have 3 chancellors for no cost then you pay for extra. You could replace
foreign minister title with
chancellor title (1 protector),
war minister with
marshal (1 protector).