You can reorder the Favorites by reordering them in the “favorites” tab on the Dashboard.
Or would you like two different orders? One on the Dashboard and one for the sidebar?
The “Sets” otherwise can not be reorderd right now.
The sidebar only shows up to 20 sets. I already made here a “bug report”. But it seems this limitation was on purpose, so I guess I will have to change it to a feature request. Therefore, it would be nice to be able to reorder the sidebar sets in the future.