Had some problems where the ball would sometimes ether go through or bounce off a direct hit but nothing game breaking.
Overall nice game
I can see why you got confused but hopefully this helps.
-The ais do their own thing with different rules, they don't build farms they just attack and expand
-You can destroy the ais bases before their built and they also attack each other (strategy is to focus on defense and make sure they don't build too close)
-If you try placing a building too close to another it will move to a position it can be placed
- Buildings outside of your area won't get damaged or do whatever their supposed to do
-The farms will regain their hay when you place them on your area (the hay is there to show you it is active)
I have already started working on improvements to the tutorial and feedback for now here are some tips.
-Every unit you can move has a banner you can pick up (hold left mouse).
-The cart spawns at the player base and needs to be moved to any of the grey tiles and when there is a yellow cart icon on it you gain a point and a special building.
The game definitely needs some improvements though.