So you found an article on chess.com, and instead of commenting right there, instead you searched the forums for a 6-year-old topic and necroed it. I see. It makes sense... oh wait.
By the way, that article's methodology has countless problems as well, but I bet that all of those are already mentioned and discussed multiple times.
https://www.chess.com/article/view/who-was-the-best-world-chess-champion-in-history