Scorpion05, thank you for that analysis. I've wondered about the differences myself, as they seem to have many similarities. Penny then showed a bunch of progress the last few games before injury.
I think the Penny burst comment is on track, with equivalent top-end speed. Neither gets caught from behind by anyone short of Patrick Peterson in his prime. I do wonder about the Penny "better hands" comment, over Prosise and his receiver background, but that's more of an "I didn't know Penny was rated as having great hands" thing.
I would add that Prosise is a better and more committed between-the-tackles runner than Penny, but now I'm not sure that's true anymore after Penny started showing improvement there.
I've been mildly puzzled by the very few snaps Prosise has gotten this year, "healthy scratch". I never felt the team really leveled with fans about the nature of his injuries, and/or the team doctors were baffled by something unique about his situation. This year seemed like the first time he actually was healthy in a long time. The team said something about how he'd had some "core" surgery during the offseason.
We'll see how many snaps Prosise gets the next few games and how Schotty uses him. Should be interesting. I suppose we could go back and review tape of the 2016 game where Prosise was the feature back in the road win over the Patriots, and guess that Schotty has seen that too and taken notes.