Personally, I don't think Teach will ever have an archeologist in his crew. It will be more in character for him to steal informations about ponelglyph. Of course, there's the problem of Robin being the only one who can translate the poneglyph. If it has to be girl vs girl, the 11th member of Teach's crew could be a woman which would be Robin's opponent, I guess.

Well, not convinced. Wainting for more.
I remember hating Franky's voice first but I just looove it now.