So I wanna talk about something that has been bugging me for a while now-the whole “asexuality” bit with Space Marines. I get the whole “they are monks” bit. And I sort of get the “implants make it so that can’t ‘perform’.” So let me take apart why those arguments just don’t work for me.
If you have read the Horus Heresy the only time they portray monks is in aspect of giving up their past to go through the trials to become Space Marines for the most part volunteers are the only ones that go through the trials so they do not cull them.
Given if they survive the trials only a handful do they have to then survive the implanting of the gene seed. As far as we know Space Marines don’t defecate or urinate and do not actually need to eat as they have a cocktail of say vitamins that they can take. They grow more organs and new organs and its possible that they lose unnecessary organs. In kind It is very well possible that a Space Marine does not have a groin. Built for war and nothing else.
As for Adeptus Sororitas see Sisters of Silence/Silent Sisterhood on the prevalence of nulls(Blanks) within mainly women.