[Kobal2]

A neat little trick to mess up enemy archer (and spell) targetting is the Lantern Shield. It summons ethereal units in the enemy's back, usually right next to their mages, before the battle even starts. Archers scripted to fire closest will target them first and a) not do much because the ghost lights are ethereal and b) make a carnage in friendly fire.

The ghost lights probably won't last long, but they only need to last turn 1. On the following turns you can cast Howl, or Will o' the Wisp, or more Corpse Candles, or Mists of Deception to keep the back lines nice and busy while your likely lads thresh through the front lines.