What makes the battle against Fredrick's men different from the battle of the cowshed?

The Battle of the Cowshed was much better planned. Snowball had studied the battle plans of Julius Caesar and outsmarted and outmaneuvered the humans. In the battle of the Windmill, Napoleon expected an attack but was not prepared. Instead of fighting and strategizing, the animals ran in terror. The animals finally stood their ground, but, unlike Cowshed, received many casualties and the Windmill was destroyed.