Sorry for the lack of clarity regarding American Sharpshooters. The rule should have been stated like the following.
3. American Sharpshooters are 2 block units and have a range 3 with one die per block. Sharpshooters gain 1 die for standing fire and no moving fire. Sharpshooters do not count as a Victory Banner.
So, in other words, a fresh Sharpshooter unit (one that hasn't taken any casualties), would get 3 dice, with a range of 3, for standing fire and zero dice if they move. When they have been reduced to one block, they would get 2 dice for standing fire and zero dice if they move.
Hope this helps to clear this up. If you have any other questions, please don't hesitate to ask.