I'm actually not sure how bright Harry's supposed to be.

He's not stupid, obviously. But, from a Watsonian perspective, he's leaning very heavily on rationality skills and an unusual reading list for an 11-year-old, Hermione seems to have him beat in some respects as far as raw intelligence goes, and being the smartest person in a class of a hundred and change isn't that great an achievement in the scheme of things.

From a Doylist perspective, making Harry get a lot of mileage out of raw intelligence would undermine the message Eliezer's presumably trying to preach.