Fulton and Gwinnett are two search markets wearing one metro's name
Content organized around named counties and suburbs generally outperforms content organized around the metro, because that is how your customer thinks of themselves.
Fulton, DeKalb, Cobb and Gwinnett are separate governments with separate permitting desks, and a homeowner in Roswell does not consider themselves an Atlanta homeowner. They are a Roswell homeowner with water on the floor.
So build the page structure around the suburbs you would dispatch to. One for Sandy Springs, one for Decatur, one for Alpharetta, each written by someone who has been inside those houses.
What makes those pages worth reading is detail only a working shop has: the age of the housing stock, what you usually find behind the wall, how the inspection step tends to go locally. Keep the regulatory parts general, because practice varies by jurisdiction and readers should confirm specifics with the local building department.
Cap the count at your real service map. Twenty thin pages for towns you cannot reach is worse than six strong ones, because thin pages produce calls a dispatcher has to refuse.