Except that isn't fair, you'll need a home and home so that's at least 90 games against the other league. Except that only leaves 71 games for your own league. Which means we'll see 2 game interleague series for 60 games, and 3-4 games series against one's own league leading to a nightmare of scheduling and travel. Or we can just add two teams, make owners richer and balance the leagues.