Archers are awful with mage build, but a solid counter is summoning parasites. Still, I attempted and save scummed the doom fortress bandit mission and its very difficult, you had to lure the out one by one. I tried the tornade ability to wall them off and blast them, but the archers spam me before I get the second hit in.
If the ai was also smarter and wouldnt go directly into my tornadoes and go around them, I could not deal even with the mele ones. I get the same feeling as with the succubus playthrough, all hell breaks loose if you dont oneshot the enemy.