I have been looking lately at the game's files and found out that you can customize certain things - for example you can make team membership selectable in skirmish/multiplayer maps were it is disabled by default.

However I cannot seem to find any way to raise the number of AI players from 3 to 7. Given that I would like to play a bigger scale skirmish the 3 AI rule seems painfully limiting. Is there any way out of this or does nobody know if/how it is possible?