It's because of the fact that you still need to make it so that the forces all say "neutral" in the player list, ok? the game can tell what teams players are on when you start a game. If you really want this map to work, though, you have to get rid of that base you made in the center. This is your first map, try not to make it that amazing, ok? you should only be working on skirmish maps with no twists except maybe more money per supply dock at this stage in mapmaking. After you make 5 skimish maps, make a couple of missions to get the hang of advanced scripting and team making, and then try the harder, new stuff. Look at me, I'm making an RPG, and already finished Part 1! Trust me, it's better to start out small (I learned that the hard way a couple of times) untill you can do stuff like that.
Here's an easier way to say it:
you get rid of the base
map will work fine
it won't work like you want it
If I delete the base it won't work like I want it.The Skirmish AI works fine.
And I dont have big problems with scripting
Play the map, maybe then you see the one error