@Catherinegsm Yes, I think, so long as Harry has any friends at all. "Some" implies that at least one wizard is his friend. If the majority of his friends are wizards, then at least one wizard is Harry's friend.

You could just imagine "most" as being a more descriptive version of "some". So it's like saying "some of HP's friends are wizards. Therefore some wizards are HP's friend." Some arrows are reversible.