fire arrows: what's the point?

[Colovion]

If the archers are shooting at an angle they will probably not light up the siege tower.
One group of archers however shooting at it directly will usually set it up in smoke, on large unit sizes.

What's with Archers having a TERRIBLE ability to not being able to hit moving units? I thought that maybe it just takes them a few shots to get their aiming on and fire forwards to hit those towers when they're plauding along. I fired 4 volleys and maybe a dozen arrows hit the tower!

[Medieval Assassin]

The point is to blow up your computer...
*holds a grunge*