I meant that that you can choose between ‘does nothing AI’ to ‘Easy’, ‘Fast’ and ‘Hard AI’. I also meant what @redrum mentioned that you can give extra money (or units) to the AI nations to make it more interesting and harder to play vs the AI in general.
The only way to improve the AI in my opinion would be making it self aware, so it will learn from playing vs a human opponent, and improve itself by doing so. I guess there are already good computer programs (chess) that are beating human opponents, even chessmasters. So to be fair there is hope for A&A fans around the globe ;)
P.S.
“Making it self aware might be dangerous, and we might get a SKYNET (terminator) situation on our hand ;)”