Yes, Triple-A Baseball should be on the list like Football League Championship in total attendance. Next, in US sports like MLB, NBA, NFL and NHL, they all have two more inner-leagues in each of league. e.g. Eastern/Western conference or American/National League. Their inner-leagues are the section of the league. They play against other division teams in a season. So the league itself is MLB, NBA, NFL and NHL. But There are no games between the International League/Pacific Coast League and MLB. So they are different leagues.