Another pertinent question is, why the Sharp/Charismatic/Vigorous hero with 8 stars and 2 scrolls and leaves, and a fine wife gets two sons of the same sort, then his line die out despite fine wifes with them as well, doctors, mistresses, etc while the Dull/Uncharismatic/langorous fools breed like rabbits even if I send them to hold a fort alone in enemy lands and quickly die from siege (Baktria has few piarcy-hunting opportunities till late in the game)

Is there any way to do selective breeding of FMs?

Including cheats, I do not mind if they make sense, and it makes sense to me that handsome and charismatic commander-national heroes with healthy wifes, mistresses, beautiful prostitutes, doctors, prime health and vigour and sharp minds would continue fornicating until they have 2+ sons each of the same sort. If I were them with that sort of accomplishments and entourage I would do little else but fornicate with as many women as possible. I know from experience that little makes you so roused as a good fight and victory.

Stupid Baktrians