An option to generate additional vassals in the realms converted from I:R

[IhateTrains]

https://discord.com/channels/612683871112396800/692883287336681592/1369378806200143893
https://discord.com/channels/612683871112396800/692883287336681592/1369381552974467183
https://discord.com/channels/612683871112396800/692883287336681592/1369439265309724803

This could probably prevent the realms from going over demesne size limit at game start.
Could probably be implemented as a game start on-action script.