A merged city and county means Louisville is not a neighborhood
When the city and the county are the same government, the city name stops carrying any geographic meaning a patient can use.
Louisville Metro absorbed Jefferson County, so the legal city stretches from Prospect to Fern Creek. A searcher in Middletown and a searcher in Old Louisville are both in Louisville and are forty minutes apart at five o'clock. One page cannot be relevant to both.
The practical fix is unglamorous. Write a page for each area you draw from, name the streets and landmarks a resident would name, and say how long the drive actually takes from there. A St. Matthews page that mentions the Watterson exits is more useful, and generally more rankable, than a metro page that mentions nothing.
Outside the merged government the buyer changes again. Oldham County and Bullitt County are separate counties with separate school calendars and different commute patterns. Families there often search with the county or town attached because they expect to stay close to home.
A rule of thumb worth holding to: if you would not drive to see a patient there, do not write a page for it. Thin geographic pages built for areas you cannot serve tend to age badly and dilute the pages that matter.