Since college graduation rates tend to closely track incoming student characteristics (academic credentials, traditional/nontraditional, etc.), this appears to be the dominant factor.
While such factors can impact graduation rates, they need to be considered in comparison to the expected graduation rates based on student characteristics. Note that another college-based factor, if the college attracts a large number of students from non-wealthy families, is how good the college’s financial aid is (affordability issues are among the most common reasons for dropping out of college), though that is more easily evaluated individually (with NPCs before application, and actual financial aid offer after admission, if admitted).