Unless I'm mistaken, it's been years since last we heard about these board games. Hopefully they'll be present during early access.
If any of you are familiar with The Witcher 1, do you remember that dice poker game where you went around the city beating increasingly difficult/reputable players? You'd start by playing against players of low reputation, such as fishermen and dung-shovellers, and as you made your presence known in the city as a dice poker warlord, players of higher reputation would accept to play with you. This would eventually lead to playing against the king.
A similar system could be replicated in Bannerlord, where there could be a certain number of characters playing a given board game. Among those characters there would be a repartition of high-skill and low-skill players, high-skill players generally being of higher social status than the low-skill ones. Just like in The Witcher 1, You could go around increasing your board game reputation in Calradia, similarly to increasing your warlord reputation.
It would be frankly a bit silly and gamey, but I think there's potential for a great little system there that could give players something to do during times of peace.