When Kipling wrote the Jungle Book he made no attempt to make the story plausible. Kipling never bothered to explained how it was that Mowgli (a boy) was able to talk with animals and we, the readers, have no problem with that. It is, after all, fantasy.
Now let's say that we are watching Star Trek and Capt. Kirk is visiting Earth in 1850 and he is in India. That could happen, Capt. Kirk has, after all, visited the past on Earth on quite a number of occasions. But what if Capt Kirk came across a talking bear who was taking care of a little naked boy. We would expect Kirk to ask the bear something like, "Gee as a bear how are you able to talk and why are you careing for a human child?" If Kirk didn't bother to ask the question, or if he did and the bear gave a really poor answer we, the viewers, would think Star Trek had hit an all time low.
My point is Science Fiction is Fantasy but it is a Fantasy that at least attempts to be somewhat reasonable. I tend to think that the best Eunuch stories are a bit like Science Fiction. All sorts of crazy stuff can happen but they should be somewhat plausible.
Anyone want to agree or disagree?