The scenario you outlined is basically worst case for PSU. Even in this scenario, they score between 90 and 100 points.
The only team that can conceivably beat that is Cornell, and to do so they absolutely must have 2 champs (not unlikely), but they're also going to need AA finishes from at least 2 of Ungar, Cornella, Fernandez, or Fernandes.
So sure, the margin of error without Starocci is smaller, but it's still significant and larger than it's been in years' past (when PSU always outperformed their expected point totals anyway).