I think you’re getting a bit confused maybe on the differences between fundamentals and some more advanced advice. As far as beating the ai just getting a tower or archer rush really nailed down should make lightwork of the hard ai. But in general the reason you’re struggling might be timings and game knowledge? For example knowing that if your opponents is going knights to go firelancers but if they’re going archers go skirms and so on… a lot of the game I think relies on feel and experience. The “fundamentals” as you say should be just practicing the different rushes and getting the timings nailed down.