Phrecklolz: Double click on that "multiplayer" tag, the list of maps come up, select any of your choosing with the game mode you've chosen in the "any type" dropdown tab under it. Then edit the modes rules on the right, etc etc.
EDIT: I was about to go on a explanation as to Skirmish not working since yesterday, its actuall working now, this second part of the message only matters if you read the first part.
how did you get the skirmish battles to work? when i choose army setup for myself and AI it wont let me click start. its only when i have the mirrored empire faction when ticking off the AI it lets me have a battle, but only with random army and only empire vs empire.