Any comparison to Peterson should end once the complexity of Griffin's surgery is understood. RG3 had both a torn anterior cruciate ligament and lateral collateral ligament repaired in his right knee, but doctors also needed to operate on his left knee for a patellar tendon graft.
The biggest concern is the damage to the cartilage in Griffin's right knee, which has now been operated on three times. It's unclear how much cartilage remains in the knee after two ACL surgeries, raising concerns of an eventual bone-on-bone condition that could end Griffin's career prematurely.
Like Peterson, Griffin is a unique specimen, but his road to recovery is an uncertain one at this time. Hard work -- and some good fortune -- will be necessary for Griffin to get back to his former self.