Ok - if they are going to learn archery, why don't they learn to use firearms? Snipers hit targets over 2000m out. Belt fed machineguns should be able to rip through almost anyone's shield. And that's before you start enchanting the stuff - autoseeking bullets, speed enhancing charms on the barrels. Of course, firearms aren't nearly as elegant as bows, but they are alot more effective and much much easier to learn to use.