No one knows how anyone will turn out. These guys haven't played a down in the NFL yet. Of those 6 quarterback chances are at least a couple won't be what the team hoped for. Or even not be the college guy they were supposed to be.Thing is I believe at least 6 QBs will be as good as Simpson next year. I could be wrong but at least they likely will not have elbow bursitis or lower back issues.
I remember how good the quarterback class was supposed to be before the start of last season. Then guys like Allar, Sellers and Nussmeir did not have the type of season expected of them. Moore decided to stay another year at Oregon. Sellers wisely stayed another year too. He'll have a chance to improve his draft stock.
Bottom line, some don't think Simpson is the guy. Rams are taking a chance that he is. He will be in a better position than Mendoza. He won't have the kind of pressure other first rounders face. And he'll have the benefit of a Hall of Fame quarterback to learn from. And arguably the best offensive mind in McVay. I doubt Stafford will be resistant to being a mentor the way Favre was to Rogers.