Even if you could disprove some of the relations he drew that doesn't mean that there are no connections and lessons to be had.

My point isn't about disproving individual relations. Plenty of time the true cause will be an unknown unknown. I point is that I distrust the field on a more fundamental level.

The interesting question is whether he could do actual predictions (and be it at a low probability level) about future events (or events he don't already know about) from what he learned.

Research suggests that making good predictions about the future needs training on making prediction and then exposing yourself to feedback.

If we want to actually do predictions, prediction book is always available.

But even if that fails drawing connections still probably enabled him to memorize all this data.

That's true. Narratives are quite good for remembering data. While I was in school and still believed in history I had no trouble to get the data from a text I read once and integrate it into an essay.