To Caleb the son of Jephunneh he gave a portion among the children of Judah, according to the commandment of Yahweh to Joshua, even Kiriath Arba, [which Arba was] the father of Anak (the same is Hebron).
A fourth group  (Joshua 15:42-44) was composed of nine cities  (Joshua 15:44).  Apparently, both this group and the following one lay between the Shephelah and the coast.  These are the non-Philistines.  And, the next group is composed of the Philistine cities.