I am not willing to project Darnold with KOC or McVay as having the same kind of long term success that Stafford has. I wouldn't be surprised if he regresses badly. If the Vikings let him go, I would guess that's why. Darnold had one of the easiest SOS in the league and was exposed at the end of the year. Neither coach is taking that guy to the SB, which is the only goal. If you want to run the stuff to get regular season wins and get to the playoffs, that's cool... but what matters is winning in the playoffs. You need a real QB to do that... and I don't buy that any coach just turns any random QB from bust to gold. If that were the case, the Rams would have never traded all the assets for Stafford to begin with.
That said, I still think it's a mistake not to have someone sitting in a room and learning from Stafford directly—even if via just watching him. Given they played well last year, I also find it hard to believe they'll just give that away by letting Stafford walk. That's awkward timing when they have the cap to pay him and still try to compete.
For Lance, I just see that as an example against trying to fix just anyone. You may get lucky and find a Baker, but it will not work more often than not. If you have the guy in the building, like the Packers with did Love... then you can move away from your QB. But to trade him away and just have no advance knowledge of how a guy will work in your building with your team and your scheme? That's dangerous. And honestly, the Rams have mismanaged things to not find a way to bring in someone to groom. Old, injury prone Garappolo isn't the solution... maybe Stetson is the guy, but seems like he has too many other issues. They also could've just traded for Fields last year to groom. They knew the contract situation coming with Stafford, so again... would be mismanagement of the situation. Stafford will come to terms with the Rams though.