My daughter is a history major. Her test scores would put her in the middle or toward the bottom of the school, but her reading/English were very high and her math and science were low. I think she’d be an intellectual equal to OP’s son as long as the discussion didn’t drift into math. She loves to talk about history, art history, religion, why a religious painting is important or why too much importance is placed on the art or artist. She likes to write about the book. The only think she doesn’t want to do is count, multiple, or divide the books, paintings, or museums.
I’m sure there are people at her school who think discussing those things is stupid when there are math concepts to conquer or sciencey things to to calculate and dissect in a lab.
I’m sure if the OP’s son finds the courses interesting that there will be other people in those courses to make discussions interesting. Not everyone with lower test scores is an idiot. I have another daughter who had much higher test scores and honestly, she’s not interested in having a discussion at all and she’d not contribute to a good discussion in a history class. She took humanities classes because they made her, not because she had any interest in them at all. She was smart enough to know she’d hate an LAC because there was entirely too much discussion going on.