On the first fight take around 5-8 knights to fight only and don't bother taking othe anything small waste of men
Level 2
Build the barracks and upgrade offensive tactics so the soilders woth the shotguns hit 9 and the knights hit 19 fight for the bridge after that the purple mines will attack you easy to destroy attack the base it may take a few times to win the battle
A good strategy for the entire game is to let them attack you until you only have 1 life left, but make sure they don't get farther than that. By that time, you should be able to send a lot out, and they won't have any men left to defend.
