Matthew Poole and continuators on Joshua 10:5

5 Therefore the five Kings of the Amorites , the king of Jerusalem, the king of Hebron, the king of Jarmuth, the king of Lachish, the king of Eglon gathered themselves together and went up, they, and all their hosts, and encamped before Gibeon, and made war against it.

This name being here taken largely or generally for any of the Canaanites, as is frequent; for to speak strictly, the Citizens of Hebron here mentioned, v. 3. were Hittites; thus the Gibeonites, who were Hivites, Ios. 11. 19. are called Amorites, 2 Sam. 21. 2. It is reasonably supposed, that the Amorites being numerous and victorious beyond Iordan, did pour forth Colonies or Forces into the land of Canaan, and there subdued divers places, and so communicated their name to all the rest.