The girls might mind their own business and/or be to busy minding the other female's business, so that may be better.
You would think that females would be equally common as males, but all to often you're right. Crossbreeding between apisto species isn't particularly common I believe. You see people popping up once in awhile claiming to have a hybrid, but I haven't seen any actually documented spawnings yet, leading me to think that the "hybrids" are just poorly colored normal offspring.