Ill-prepared melee characters may have a problem with them as they can cause blindness with Throw Dirt. As they are enchanted pieces of armor they have no flesh and are immune to bleeding, poison and disease but have a weakness to lightning damage.
The elite skill Marksman's Wager used by Enchanted Bows causes energy loss on a missed attack. If you can blind them after they prepare Marksman's Wager, it would render them somewhat harmless. Plague Touch is effective for melee characters in this regard, clearing them of Blindness and rendering the Enchanted Bows unable to attack and out of energy.