It is definitely possible. However it might take quite a bit of fidgeting in the code. i've looked around some and the way i see it there two genders in current pronoun coding (in the game there are 3, but bear with me here). There's a male and there's not male, so basically futanari has female pronouns because it is not a male.
Now to achieve what you want you could change it around. So everything that IS female will have female pronouns and everything else will have male. If you really want to test it out i can give you pointers what might work according to me and it will be up to you to test it ;]
Of course I might be totally wrong and there might be a much easier way, or my way will totally botch things up. I've only started to mess with s4p so i don't claim i have full understanding of scripts here.