Make settlement culture based on several inputs instead of just based on player rep and painting culture.
for example: towns 50 points total
-- 10 points towards culture for the top x number of properties in the settlement and how much housing bonus they have combined.
-- 10 points towards culture for average food bonus for active citizens
-- 10 points towards culture for settlement foundation deed culture
-- 10 points toward culture for highest or top 3 or what have you rep of citizens.
-- 10 points toward culture based on the number of active stores in the settlement
-- 10 points toward culture based on number of trees planted and living in the settlement influence
-- 10 points toward culture based on the number of asphalt / stone roads in the settlement influence
-- 10 points toward culture based on the number of streetsigns / stopsigns / streetlights etc
just a few ideas to make culture not so linear.