Lowering the indept strength can make the AI much stronger. Try a setting of 5.
Making a copy of the .map file of your favorite map you can add commands which change the AIs. Such as pre-designed gods and scales.
One of the things I like to exploit about AIs is that I send stealth troops to where its fighting another AI and snag provinces when they both have ruined their armies on each other. There are commands you can add to the .map file which will ally AIs so they wont attack each other. If you want to try a small game like that you can login to one of these.
http://game.dom3minions.com/bin/vsAI_chk.cgi
Since AIs are in the game you can go ahead and hit START right away, or wait for more humans to join.
You can also use map commands to grant extra units and castles. If you want to try that taken to an extreme you can login to one of these games.
http://game.dom3minions.com/bin/Chaos_chk.cgi
Again you can start it right away and play by yourself, or wait for others to join.