If, say, 10% of the students who were admitted this way succeeded would you change your mind? To me this sounds like the faked credentials allowed the students to skip the first filter (admissions), but that there was a second filter (top tier classes) that most of them failed.
https://washingtonmonthly.com/2000/09/01/playing-with-number...
She was shocked at how poor the actual academic standards at the latter "prestigious" organisation were - even though everyone spent a lot of time congratulating themselves for being at a top law school. It was much more difficult to get into that law school (unless you were "connected" of course) - but they really didn't expect much of people once they were there.