Help on map please!

Hello. I have made a multplayer map but have a problem. I have a computer player in the map as player 9. the players 1-8 are people. I want players 1-8 to be on different teams but be able to ally/unally in game at will and not be able to choose race. For some reason I cant get this to work and I tried everything. players on 1 force comp on another, all on the same force, modified allied settings, custom forces, fixed player settings or none at all. When I play either everyone is on team 1 and i cant start. People can choose race. Or the game starts but the allied menu is blocked out so nobody can ally at all. Its sort of like eurp wars for SC where you pick allies in game and break them only with a comp mixed in. Can anyone help me? I tried everything! Thanks

I dont know if it can be done. but then again, ive never really tried...