There is a difference between חצרים (villages) and ערי הפרזי (unwalled towns): חצרים are villages in the field where the workers of the land live. And ערי הפרזי are cities in which there is no wall, cities of at least three courtyards, each containing two houses.

And the language עיר חומה(walled city) is not found anywhere in the Hebrew Bible, onlyעיר מוקף חומה (city surrounded by a wall). Thus, when it is written בית מושב עיר חומה (dwelling-house in a walled city)⁵⁹⁸, it means that it was sanctified with the holiness of a walled city.

footnotes: ⁵⁹⁸ Leviticus 25:29.