Arrows in Heroes 2.

But if you block the Lich, there are no Archers left to take out other Archers!
And while that's happening, the undead are getting pummeled by the enemy Archers...

If you think about it that way, then only the Tower is really worth something, because it has 3 Archers. :)
If someone blocks your Lich, you need to take out that guy, and use Flyers to deal with the enemy Archers... and there won't be any problems... :)