If you are in a team on the main menu the leader should be able to pick a server with enough open slots and the team should auto join

I echo your concern. I was extremely frustrated not being able to join a match as an entire team by selecting the server I wanted. You are FORCED to use the games "matchmaker" to find a game and then it will pull the entire team into the match with you. The original Insurgency (and every other server browser enabled game, for that matter) has allowed you to do this for years.