Two things..
1) Peterman throws down the middle. Something Tyrod cant do to save his life.
2) Dak Prescott was also drafted in the 5th round (essentially, he was pick #37 in the 4th)
The Bills may not have the cowboys' pass protection, and Dez. But the run game is just as good.
Peterman can definitely make do with the receivers the Bills have.