Welcome to BigSoccer. Not many new accounts these days. One size fits all solutions are generally a bad idea. There aren't any good "10k" stadiums in the NYC area that would be appropriate for an NWSL team. Red Bull Arena is really hard to match for both the fans, the participants, and even the viewing audience. You are correct that huge swathes of empty seats can be problematic, but then so is the sight of rows of outhouses in the gravel parking lot clearly visible on a broadcast of the game, and asking professional players to bus offsite for a shower after the game.