I went to a school that only had 4 or 5 full-time CS professors. There were also a few math and EE professors who split their time between teaching their main subjects and CS. It didn’t have a huge menu of classes, but it had enough to be a legit CS program. That’s why I originally suggested looking at the classes that were offered rather than focusing on the number of professors.
At the undergraduate level, you don’t need CS professors who are absolute experts in everything they teach. They just need to know enough to convey the general-level info that undergrads get taught. Kind of like in the land of the blind, the one-eyed man is king.