I'm new to this, so I apologize in advance if this is the wrong place to put this topic, but I'd like to alter the game files so that the chances of a successful Mongol/Jurchen invasion of China will be zero, effectively ensuring that the culture of the off-map Chinese empire will remain Han in all scenarios, unless the player invades with their own realm. Can this be done by a casual file editor, and if so, how? Thanks.