Charisma is kind of a dump stat under SS, with settlement population limited to city plan maximum by default. Maximums range from 10 to 15, meaning the most charisma that SS will make use of is from zero to 5. It isn't unreasonable to have 15+ charisma all the time on a character with their base statistics and vanilla equipment.
Of course you can override this and manually place more plots if the settlement area has room, but it would be nice to have an incentive to leave city maximums in place and let them do what they're supposed to do, and still leverage high charisma. Please consider using an alternative mechanic for making high charisma valuable to settlement leadership, the most obvious being a settlement happiness bonus, but maybe also things like:
- income bonuses from commercial plots or taxation (possibly dependent on charisma perk picks)
- larger happiness bonus for recreational plots
- combat bonuses for guards similar to companion cha-based bonuses (again possibly dependent on relevant charisma perks)
Of course you can override this and manually place more plots if the settlement area has room, but it would be nice to have an incentive to leave city maximums in place and let them do what they're supposed to do, and still leverage high charisma. Please consider using an alternative mechanic for making high charisma valuable to settlement leadership, the most obvious being a settlement happiness bonus, but maybe also things like:
- income bonuses from commercial plots or taxation (possibly dependent on charisma perk picks)
- larger happiness bonus for recreational plots
- combat bonuses for guards similar to companion cha-based bonuses (again possibly dependent on relevant charisma perks)