This was so eye-opening for me! I don’t use Twitter and I don’t follow basketball, so I found it extremely surprising that I have observed a very similar trend in a completely different topic: K-pop. K-pop, if you don’t know, is Korean pop and over the years (with artists like Girls’ Generation and Psy) has spread all over the world. A lot of K-pop groups are actually comprised of 5, 7, or even 12 members, so there DEFINITELY are certain groups that are more in the spotlight because of specific individuals within those groups. Those individuals really carry the name of the group, provide financial income for them and their agency, and have the most followers on social media. So while I don’t have much to add to your observation, I thought it was really interesting to witness such a similar phenomenon in a completely different field.