McVay said it right after the draft. That it was LaFleur and Robinson that targeted Stetson from the very beginning. All he said at that time was he liked his throwing motion. That's a far cry from what he said about Mayfield as someone he followed and liked. Stetson doesn't have the arm for McVay's normal scheme. Too many of his deep throws are rainbows and make the WR adjust. Go ahead and watch his pro day, many of his throws were catches because of the WR adjusting, which he might not be able to do in actual coverage.
That said, in a more normal offense, being able to drive the ball 20 yards with accuracy is really all you need. You do that and the WR will often get good YAC. I think Stetson will be a very good backup, but I simply don't see him making the throws in the way that Goff or Stafford can. I think Stetson is viewed as being a decent backup and a future comp pick or trade bait.
IMO Snead and McVay have targeted a QB in next year's draft that will be their future QB1. I've said in other posts, that if the Rams didn't get a clear future QB1 in this draft, that future franchise QB would probably be targeted next year. I don't think McVay or Snead sees Stafford playing beyond 2024. I think they saw that when they extended him and the contract is structured that way. It's also obvious that Stafford understands that and wants those 2 years to make another run at a second Lombardi.
As long as the Rams have a healthy Stafford and Kupp their offense is dangerous enough to make a run. Their defense simply needs to be in the top half of the ratings, not the bottom half where Morris dropped it.