Team settings in skirmish/custom game mode

Skirmish mode against the AI has always been my favourite part of Age of Empires. I like to play with 7 other AI’s on a huge map with no water so it’s a pure land battle. I set all the teams to “-” and lock them so everybody is an enemy.

So every game I play in skirmish mode in the definitive edition so far, all that happens is all 7 AI’s go right for me. 20 minutes into the game I have 30 or 40 villagers and a large army of axemen, slingers and archers, and lots of towers (because I like playing as Rome).

…and every AI in the game goes right for me. Seriously, every game, within 20 minutes of the game beginning every single AI faction is in my base with 20 or 30 units. It’s impossible. What do I have to do to the team settings to make everybody fight each other instead of just going right for me?

In previous AoE games I just set each team to “-” rather than 1, 2, 3, 4 or ? and that would make it a free for all. In this one though it just makes all the AI fight me rather than each other.