My strategy for archers is to stand near a wall or some other kind of large object you can duck behind after taking a shot at em. Near the end of the game I took out archers with a fire ball and one or two magic missiles but take your shot, run behind cover, they should've started shooting when you were out of cover so the arrows will hit the wall (or object) you hid behind and you pop right back out and take another shot. Rinse and repeat till they're dead. Plus fire ball and magic blast stun so you can take maybe two or three spells (you'd be pushing it with three) before getting hit.
But explosive arrows are overpowered i agree -_-. You run into three archers, i had 700 life and I was down to 200 if not near death after all three took their shot. And that's before you get stunned so whatever other stuff you might be up against gets to take potshots as well.
