Namely, that Snead/McVay have established a helluva 3 year track record of both finding and quickly developing quality football players in rounds 2-4.
So, why shouldn’t we feel confident that they will continue to do so is this 3 round deep draft?
As to your other point? I don’t think that the Rams are hoping for ‘their’ players to be there in each round.
I think that the Rams have multiple similarly rated players targeted near their pick points. IOW, Rams aren’t necessarily interested in only one player at each decision point since they may have a dozen or so more or less equally rated players sitting there for them, perhaps at multiple different positions. This enables Snead to sometimes trade down knowing full well that one or more of ‘his guys’ will still be there after trading down. What incredible flexibility that gives Snead!
It all comes down to having the ability to accurately evaluate these players. Snead and his scouting dept seem to have that ability and that makes them golden.