That seems like it was possible precisely because of the additional teaching help though. If there were only 4-5 professors teaching per semester, it would be hard to offer enough courses regularly it would seem to me. I agree, you don’t need super experts in every course for undergrad. But I think there is a notable gradient between your basic sufficient CS program and MIT, one that the OP’s son would be well suited for. That’s not to say you can’t be successful at a school with 4-5 professors and a smaller program with a middling selection of courses, but the path has a lot of advantages from those second-tier CS schools, like Case and others. I’m hoping the OP can shed light on the selected colleges thus far to be able to identify good options in that tier.