Pleaselog inorregisterto add a comment.
From what I have observed your secret base will keep the first 3 Pokemon at the time of your friend meeting you, through street pass. The only thing you do not keep is your Pokemons levels but you can get them by using the item I think is called a level release. If you mean the friends in your base than no sorry. They are preset and the only thing you can custermise is their levels (which are based on the levels of your own Pokemon) To get their teams over level 50 then you will need a level release. If you really want to change their preset teams you could ask your friends to change their image (like biker, ace or swimmer.)