I think that kind of exercise tends to teach bad habits. In my experience with the AI, it is very good at punishing naked expand, poor at dealing with protected expand, and itself tends to expand in a naked and vulnerable fashion, often taking too long to rally its forces to counter your raids.
In contrast, a human player can't pay attention everywhere at once so you can get away with a lot of naked expand, specially if you're distracting them by playing aggressively. Human players deal a lot better with defenses, even if its just llts. Human players respond much better to your own raids and can actually try to outmaneuver you and cut off your retreat, potentially turning a raid into a loss, which is something the AI will never do.