[Baalz]

That doesn't seem right to me, but I'm not going to run a bunch of tests to prove/disprove your hypothesis. Without the storm the archers would have had a precision of 2 instead of 1 and half the arrows wouldn't have been negated. The precision difference would have been pretty much insignificant so the archers would be about twice as effective without the storm. Twice of very ineffective is still pretty ineffective.

Is darkness an effective archer counter if you're marching a block of 500 militia at the archers? Of course not. Is it effective if you've got 50 heavy guys spread into 4 groups? Indisputably - a *lot* of the arrows hit empty ground even from relatively close range. If we're not under a storm it's even more stark because fliers instantly spread out all around trying to attack rearmost/archers. If you're engaged in melee, friendly fire will be as bad or worse than offensive fire.

With mages its pretty stark as well. Watch a mage trying to hit a clump of vamps with blade wind as they're trying to get through his bodyguards a few squares away. Invariably lots of dead vamps. Watch the same mage try it under darkness. Very few vamps will get hit by more than one blade and lots of the blades will hit dirt. Same is true of most spell, it's just most noticeable with the large number that come out with that spell.