I think that a game with the level of Top Eleven should have a easy feature to organize tournaments of different styles.... and I think it's a issue that we can't add friends in-game from any server, so...
We know that the FAs feature have no restrictions so the feature could cnsist in have a simil of the FAs but in a Friendlist style, "so have a club of fans-followers/supporters" designed in a FA style, so eliminating the server/level walls, and, ofc. we need a way to create private Friendly Tournaments easy.
This feature could even include future events, allowing us to join with friends different challanges or facing 2-3-4 groups of friends inside a same event after invite them to join with us.
I think would be interesting after 10 years of top eleven eliminate the server barriers.