The words "horseman" and "archer" here are generic nouns that refer to a group of horsemen and a group of archers, not to one particular horseman or archer. Alternate translation: "horsemen and archers with bows" (See: [[rc://en/ta/man/jit/figs-genericnoun]])
These two clauses have similar meanings. The second one strengthens the thought in the first. Alternate translation: "The cities will be empty. There will be no one left to live in them" (See: [[rc://en/ta/man/jit/figs-parallelism]])