here is a quick synopsis of what I found. You can add multiple leagues from many historical leagues. I skip the regular season and don't schedule spring training games (Link below).
http://www.ootpdevelopments.com/boar...d.php?t=288057
I have a playoff of all team in the leagues, but you can disable playoffs as well.
Once all this is done and no games are scheduled for any league you can create a tournament league utilizing teams of the current leagues. If the leagues are scheduled for other games teams won't fully be able to participate in your tournament since they have other games to play as well.
Note, each team can only participate in one tournament. I found this out the hard way as I wanted to create a league with multiple tournaments only.
I do agree that more information or tutorials will be useful for this new feature.