#3 Carmella

Carmella might not immediately come to mind as a great opponent for Charlotte Flair, as The Queen is known for her excellent in-ring abilities, and the former 24/7 Champion is known for her entertainment value.
However, with Carmella lingering in the 24/7 title picture alongside R-Truth, it might be a good idea to give her a rest from being Truth's sidekick and give her a run as a challenger to Charlotte Flair's title.
Carmella is a former SmackDown Women's Champion herself, having won the title after she cashed in Money in the Bank, so a return to the title picture might not seem out of the question for the Staten Island standout.
Carmella has seen very sporadic in-ring competition since being paired up with R-Truth, and her winning the 24/7 title was fun, but is also becoming a bit monotonous along with Truth running the 24/7 title scene.
Splitting her off from Truth for a while so she can get back to in-ring action might be a good way to freshen up Carmella.
The duo of Carmella and R-Truth could eventually reunite, and it might even be a good idea to pull Truth away from the 24/7 title for a while to give other talents (or legends?) the opportunity to have run with the Championship.