I dont know if its an error. I started a 2vs2 Team ladder game lately, with a teammate of me joining - open for an other team to join. Now I can see that the other team is called "Warlords", which is an existing team, but no player has joined so far. I suppose that a player of that team joined the game and leaved later on. Now the question is: are the player slots blocked to that team, or can there be another team joining?
Game is called "tryoutteamladder" and is still open.