Hazor being the most important city is spoken of as Hazor being the head of the other kingdoms. AT: Hazor had been the most important of all these kingdoms" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/translate-names]])
The word "he" refers to Joshua and represents himself and his army. Completely destroying every living thing in the city is spoken of as if those living things were dedicated for destruction. AT: "the army completely destroyed them" (See: [[rc://en/ta/man/translate/figs-synecdoche]] and [[rc://en/ta/man/translate/figs-metaphor]])