Yes very good point, that is indeed a fundamental piece of doctrine and a good example of the erasure of women and queer people from the teachings. I remember puzzling over this myself a long time ago and wondering how I was meant to apply it.
Similarly with the Vinaya rules there is an absence of clarity for same-sex attracted people and a real lack of practical guidance. I remember one of my vinaya teachers telling the several gay/bi guys in the room to practice by simply swapping the gender in our rules. Though I appreciated the attempt at at least recognising there were queers present, it really isn’t the right way to go, because firstly it simply isn’t practical in an all male monastery to pretend all the men are women and not be alone, or travel together etc. And secondly it doesn’t work because we aren’t allowed to interact with women as if they were not covered by the rules, which would simply leave me in a weird wasteland of loneliness or in a hilarious twist, surrounded by other gays! And the poor invisible bi folks would be utterly stranded!
It’s so strange that though the Buddha was aware of same sex attraction he never made such rules to clarify. And it would be unthinkable for a group to suddenly invent their own Vinaya rules as my teacher suggested above. Given the massive corpus of obsessive detail some of the rules go into, it really is surprising that there is zero mention and therefore zero textual guidance for non-straight monastics.
Thank you for also pointing out the erasure of women from the 3rd precept. This is a good example of a text really not speaking to a huge segment of the community. It really does seem like a curiously odd omission.