Lemme tell you, there is no borderline. They are bullshit and you must embrace the bull shit to win.
I remember one specific campaign I was stuck until I had the thought to tc drop the ai then won.
Then there was one where you had to like escort 5 different transport ships from the edge of the map to your base, and before each wave came you had to speed run to make a path. I saved after each successful wave so wouldn’t have to start over after each fail.
Another one was like “no castles or walls allowed! This is about army” but they didn’t block building bombard towers, so…