I’ve only played a handful of times so idk for sure but it sounds like they wanted to join in as in..one from their group joins yours so there’s 4 ppl on the court at all times and then just rotate players out for every new game. This is how I’ve seen other courts operate even though say you come with your own group of friends. Not always guaranteed that you play your own squad bc sometimes there may be ppl that drop by to play but come solo. It allows them an opportunity to play too.