It is implied that these men were Israelite soldiers. Alternate translation: "The whole army of Israel ran away from the Philistines" (See: [[rc://en/ta/man/translate/figs-explicit]])
This is probably a generalization. It seems that while all the soldiers did run away, not all of them died. Alternate translation: "Every man of Israel ... most of them died" (See: [[rc://en/ta/man/translate/figs-hyperbole]])