How do you beat Autumn War?

Just do the Hit and Run Tactics

What is Hit and Run? If your asking

Hit and Run is to inflict the target while not taking casualties at your side

and immediately flee the area before the enemy returns fire

But in autumn war order your men to hold their position and engage, If the enemy is about 4 meters to you you'll need to order your men to fall back(retreat)

Do this if you know the enemy will overrun your men

Hope you Succeed