At this point he's wayyy closer to Sanchez than he is to Pennington.
He's nothing like either of those two players. Pennington sat for what, 2+ seasons and just learned. That dude was always going to go as far as his brain took him. Sam didn't sit and doesn't have that kind of brain (most QBs don't).
Sanchez was a proto-typical game manager, Neil O'Donnell style. His first two years in the league, all he had to do was not give the game away. He had an absolutely DOMINANT O-line (D'Brickashaw and Mangold in their primes, along with rock-solid vets like Faneca, Brandon Moore, and Damien Woody). He had Thomas Jones and Ladainian Tomlinson to carry the rock. He had Cotchery, Braylon Edwards, Santonio Holmes, and Dustin Keller to throw to.
On defense, he had prime Revis and guys like Leonhard, Kerry Rhodes, Bart Scott, David Harriss, Shaun Ellis, & Cromartie.
He even had a special teams/gadget freak in Brad Smith.
Sanchez fell off the side of the world when they assumed he could carry a team himself. Instead of Jones and LT, he had Shonn Green. Instead of Cotcherry, Holmes, Keller, and Edwards, he had Jeff Cumberland, Stephen Hill, Chaz Schillens. The O-Line still had Brick and Mangold, but the three guys around them got older and/or weaker. On D, Revis, Leonhard, and Rhodes were replaced by Kyle Wilson, Yeremiah Bell, and LaRon Landry.
TL/DR, they started to rely on Sanchez to win the games rather than to just not give them away. And he couldn't do it.
Darnold doesn't even have
close to the same supporting cast. Bell is no Jones/LT. The BEST O-lineman on today's team wouldn't even start on those 09/10 teams. Herndon is no Dustin Keller, and that's even when Herndon could go near a field without exploding with injuries. The WR's aren't that much worse, but there's no #1 guy, really. Just like 2012, it's a whole corps made up of slot receivers and one-trick pony's. The only 3 guys on defense who could have hung with the D back in Sanchez's first couple of seasons are Mosely, Adams, and Maye, two of whom can't stay healthy.
Before writing off Darnold, I want to see him with even HALF of what Sanchez had covering for him back then. This team needs to replace the entire offensive line, the entire secondary outside of Adams, and then rebuild the defense and the receiving corps.
Darnold, as one of the youngest QBs in the league was expected to carry the team on his back with almost no supporting cast. I'd be seeing ghosts, too.