Russian roulette with a Talaxian penis?
There are plenty of NPCs but it's a double blind, no one knew they were fake or anyone else was fake, although we're sure the doctor would have maintained any contraceptive regimes unless some of the crew preferred against contraceptive for some perhaps moral or religious reasons... Oh and half the crew was confined to quarters, probably including Naomi.
We saw one (might have been two?) crewmen pronounced in the sickbay where the doctor pulled a sheet over their face because it was time to give up, and how can we be sure that we didn't see any female Hirogen? The differences between genders might be too slight for a human being to notice... Although one of the Alphas did make a sexist remark to Janeway, so maybe it was just as big a boys club as it seemed.
Although if the problem was that the Hirogen were too busy hunting that they forgot to breed, what sort of shit poor practice run was this that they didn't have any girls on board to help with the whole saving the species prospect?
"Couldn't arrange an orgy in a brothel"