[chrispedersen]

MAximum distance to miss by never exceeds actual distance.
The amount missed by will also be a bell curve - so the amount missed by is actually fairly small.

When an archer mass targets a large mass of enemy troops, the vast majority of missiles target the middle of the enemy lines (especially if there is the prospect of causing friendly casualties).

This tendency *increases* as the distance decreases.

Do a straightline comparison between combats (for example by introducing a unit that autocasts darkness) and you will see that for many combats darkness makes essentially no difference in combat results.