I have no problem with Robin 1v1 one of the female flying six members and I really want her to get a 1v1 fight, however I don't know how to feel about Nami 1v1 the other female flying six member. The flying six are the strongest headliners and are right below the All Stars, look at what Page One did to Sanji.
Then you have the veterans of the BMP such as Perospero who easily defeated Brook and Chopper, and Daifuku who easily pushed back Sanji.
I have a hard time seeing Nami 1v1 a flying six member, if she has help then that's fine but if she doesn't and she actually manages to defeat one of the female members in a 1v1 then I'm not too sure how I would feel.