its also possible to alter the style of play the AI uses in the campaign. in the startpos txt files each faction is assigned a style such as catholic crucader or muslim expantionist. the file kindly gives you the entire list of those avaiable
an example here is changing the Byzantines from orthodox_stagnant to orthodox_expantionist. this makes the AI Byz far more competitive, especially in early, and allows them to conquer the Turks almost every time, so you end up with a strong byzantine faction covering most of eastern europe, creating a massive clash of the titans once the mongols invade
if you remove the trader part from Italy, changing it to catholic_expansionist, you remove a lot of the annoying naval problems that suddenly becoming the enemy of italy can produce these are fairly simple changes to make, but they can in some cases have profound effect on gameplay.


as an additional query here to a more experianced modder, if you changed the papal description from papacy to catholic isolationist would the game/papal faction
a) crash
b) remove papal restrictions like excommunication
c) make the papacy a competitive faction adjusting the balance of power in italy
d) a combination of these