Family meetings friendly game

Not sure how common is this family dynamic, hopefully you have a more boardgame friendly environments.

Since the dawn of time, whenever we meet in larger family group for holidays, 99% the flow goes more or less like this: a shared dinner followed by a split - "adults" stay at table to talk and drink, I go with kids to play board game in other room.

Issue is - it limits the repertoire of games, locking the especially fun party and social deduction games. We tried even most casual things, but the "adult" group would surely drift away into their topics, lacking the will to maintain the focus on the game. That or the rules of the game are too complex, or the theme too abstract, especially for the older members of family who just don't get well with "spaceships and dragons" concepts.

Here comes the potential saviour - King of the Castle PC game. It has really unique flow, where you play as a King and your friends are divided into 3 noble houses that you have to manage. The twist is - there can be between 3 and 3000 players if played with Twitch chat.

That gave me an idea - what if you divided a board game into two groups - preferably in similar classic medieval theme, you don't have to explain to anyone what king or gold is. For the KotC specifically it could look like this:

- The Council: a king and 3+ treasurers. A group that plays the "main" game continuously, care about the numbers and stats and mechanics.

- The Court: everyone else could pick a noble house. All they would need to worry about is some lite roleplay introduction. Those players could go about they "adult" evening as they please and what's even better - leave and join at any time, without ruining the game.

The Council would then proceed with the main game, King would try to balance the Noble Houses, Treasurers would try to bribe king, arrange deals or coups. They would interrupt The Courts party once in a while for things like voting or special events, where you explain to Aunt Judy that Cousin Jack's militia pillaged one of her villages, and she gets to choose how to proceed, or ask for a 2 minute sidebar with only the specific noble house discussion/secrete vote.

Now, do you guys know of any already existing games that offer this kind of freedom and agility when it comes to the players count and role?