I think we should add borders to rimworld which would make going to certain areas (pirate territory) dangerous and more likely to get ambushed by a big group while being a bit more safe in friendly outlander land.
It would be more realistic, because real factions have generally their own territory.
Do you have an idea of the size of these areas ?
Keep in mind it' better to avoid to create an area where it's too difficult for the player to meet different factions.
They could all be different sizes