Dru Brown is 3x the quarterback Prukop is. Prukop is a great athlete but you really don't want him starting.
Ya, Brown may yet be a legit #1 (long shot, but possible). Prukop clearly was just a SY / special package guy, and not even as good at it as Strev. But he was a very good SY guy, and thus losing him is a downgrade for our team unless we get an equally capable replacement.
In the PS/garbage-season games they started Brown clearly looked better than Prukop. I liken Prukop to LeFevor: great SY, but stunk as a starter. Even Dom Davis would be a better starter than Prukop.