#4 WWE SmackDown Women's Champion - Sasha Banks

Bayley and Sasha Banks' entire WWE main-roster run has been building to an inevitable showdown between the two friends. They tore the house down in NXT, setting an extremely high bar that changed how things were done with female performers in WWE.
The current SmackDown Women's Champion had primarily been a face throughout her WWE tenure, but she had a character shift last October that saved her career. That shift also netted her the SmackDown title, a belt that she has held for almost a year. That makes her the longest current reigning Champion in all of WWE. Banks' return helped to facilitate the heel turn and the friends were staunch allies ever since.
Female superstar says she inspired John Cena turning heel HERE
There were brief moments where there may have been some dissension between the two, but things worked out. That was, however, until Banks lost both of her titles and Bayley turned on her friend. The brutal attack a few weeks ago on SmackDown was due to jealousy on both sides and the fact that Bayley thought the Boss had "outlived her usefulness."
The former Hugger has defeated every challenger she's faced and she's defeated a few women (Lacey Evans, Nikki Cross) more than once. There's only one name currently active that makes sense to dethrone Bayley and it's The Boss. It's well past time that someone else has a run as SmackDown's top woman and it will be Banks that gets that opportunity.