Don Mafia,
By your post, I assume you are female. I do agree with you that womean certainly have the brains and aren't as hotheaded (usually)as men. It's not that I wouldn't think women would be capable to be the brains behind the organization, but I can't picture them being the "muscle", so to speak, and be taken seriously on film.
Personally, I would see a mafia movie with women in the lead, but my preference would still be male, maybe cause it's more true to life, I don't know. Or maybe because I just prefer looking at males!!!!
TIS