Apparently I'm not being clear. It has been implied that not giving the We, specifically, this job is morally wrong. I am saying that no it is not. It is also not morally wrong to not give the job to anyone else but that argument hasn't been made so I haven't argued against it.
'Outright the best candidate for by any other metric' is an opinion, and it is one I don't share. Forget the We for a moment and consider a librarian with the following characteristics:
-can reach books extremely quickly, even in a large library
-is literate
-immortal
-intimidating
-has never seen a library in their life, possibly doesn't know what that is
-previous skills include hunting and weaving
-has been a hermit most of their life, has very limited experience with any society at all (though they did read some books)
Is this outright the best candidate for librarian? You can think so, but I think you'll have to admit that it's not all positives. There are some attributes here that don't scream 'librarian' at all, and on which other candidates have a clear advantage.