Once Jean left, it was over for the group. I think of the Supremes as like a train in this scenario, a steam locomotive. Once Diana jumped off, there was still enough steam to continue on thanks to what Diana, Flo, Mary, and Cindy had previously done. Add Jean and her voice, and a pair of great songs [[Ladder and Stone Love) and you’re able to steam ahead for a while. Remove Jean and that’s where the trouble begins. By this time, in a group of 3 members, where everyone has been replaced except for one person, it is no longer the group that people love. It is a group only in name.