May I suggest building a trench-type waterless moat, either around the area from which they spawn, around your area of operations or simply between yourself and the path they generally take to get to you. Kite them into the trench when they do attack you, or get them between you and the trench then shieldblock/parry them, so they are knocked backwards into it. Don't kill them just leave them there. If they remain alive it should reduce their spawning frequency.