The anecdote proves nothing because the model could potentially have known of the McGonagal character without ever being trained on the books, since that character appears in a lot of fan fiction. So their point is invalid and their anecdote proves nothing.

That’s only because he didn’t have an opportunity, not because he’s some arbiter of peace.

Marx had two things: a critique of industrialist society, and a plan for how to fix said society. His critique was valid, his solutions were questionable. I don’t think you’ll find many socialists today who consider themselves Marxists.