I like to see it as a rule of thumb, needs 2 shops, 1 hotel, 1 pub, then 4 houses are needed for the workers. A central point (like a fountain or statue) and water, somewhere, even if it's a well as the centre point
Then extra houses as far as plot is concerned.
Even the smallest town needs to look like people live there. And ironically small towns have farms, garden, temple
Bigger the town, the more unaccesable houses.