Yeah, but just to be clear there's only ~1500 classes offered there. The 3000 comes from many of the classes having multiple components, lab etc.

The number is further reduced by the fact that many of them are the same class with special qualifications to ensure placements. For example intro classes for designated transfer students. So you have the same class but 10 seats or something are only available to certain transfer program students.

The real number looks like somewhere in the ~400-600 range. Which is still very impressive but 3500 different intro subjects would be wildly excessive.