So I figured out how this broken mode actually work 1st if you and your friends are on the same console or the people you randomly join with you can use any of the cards on the game I have tested this theory but the problem comes when you run squads with friends on a different console and try and use season 2 players me and my friends tried this method out and every time we would play with a PS friend we had to take out the free season 2 players the 4 87 overall cards we get and it works fine but keep in mind if others don‘t Switch them out and they are cross playing as well the game won’t start.  So as long as you are all on the same console any players are fair game.  Hope this helps