Necromancer versus Light Elf.

Are there any other options?

My aforementioned tactic with Chaos and Light.

Next:
Scatter is cast on everyone (or almost everyone). Sure, a hero can remove it from the archers with antimagic. So what? Will he just move around with archers? And I just happen to have a hero with the next spell, Subjugate, ready to target those standing near the archers, most often these are Ents (thanks to skillful spellcasting, spending half the turn due to the massiveness of Darkness and distraction) :D