Its based initially on same level, same server friends and mutual friends.

You can change things, if have such friends that reappear each season, by ditching them or by adding new ones to get fresh blood in your friends list. If you have no such friends then add some.

A problem can be that ppl add league rivals as friends which strengthens the bond between teams and increases the likelihood that the top 7 wil repeat things. Adding same level teams from CL or Cup can freshen things up.