This question was closed as a duplicate. I have edited to add a couple of paragraphs explaining why I do not think the alleged duplicate is relevant.
In brief: I am asking for a word that describes a person (possibly extremely knowledgeable) who makes arguments (possibly citing all of that accurate knowledge) that are highly articulate but actually make no logical sense.
The duplicate seems to be asking for a person who is not knowledgeable, but pretends to be. That is not at all the same thing.
One difference is that I want a word that implies "articulate"; I don't think the duplicate is asking for that. Another difference is that I want a word that applies even when the person is highly knowledgeable; I don't think the duplicate is asking for that. Another difference is that I want a word that applies even when the speaker has no intent to deceive; I think the duplicate (or the posts around it) largely do assume some intent to deceive.