The downward curve of finding a starter is steep after round 1. That's just the math; there's no denying it. Later round picks have a low probability of ever being a starter. Of course when the League has like 1700 players, many starters are late round picks, but not as compared to 1st and 2nd round.
It is useless to point to the Tom Brady's, Antonio Brown's, etc. as what can be found in later rounds. Essentially what most of those were, were bad evaluations by scouts and GMs who are paid to find the best players.
The thought of "waiting" (implication is that it is intentional) to pick a WR in the later rounds when a starter is NEEDED, and when almost for certain a potential starter quality guy will be there at the top of round 2, is faulty logic. A need is a priority. You don't put off priorities until later if you want to keep your job.
The Rams NEED a TE, WR, and Center. Then hopefully there are 2 of the 3 position players in rounds 2 and 3 who are worthy of that pick. According to the draft gurus, CB and WR are deep this year, and to an extent so is TE. But as usual, all the teams know this. That means that those who have needs in that direction are going to line up at the trough for rounds 1 and 2 for these guys, and so some other positions might slip into the early part of round 3. Who doesn't need a WR or a CB? So if anything is going to "slip" it is (as concerns the Rams) possibly the TE's and Centers.
I think the Rams are going to go for WR and TE in rounds 2 and 3, but will be open to CB if one they really like for Phillip's D, and they have high grades on, falls to them.
What is unpredictable is when there are "runs" on players. Happens almost every year. It looks like there will be plenty of position "A" to go around; but then teams that weren't expected to go for that position do, and then that position group gets hollowed out in a hurry.
Rams: be smart. Go for the WR or CB in round 2: which ever one that your board says is CLEARLY the better prospect. But if the board says that a CB and WR are pretty well grouped as equals, for Pete's sake get the WR. The most important thing this year revolves around Goff. a) give Goff more weapons, and b) give Goff better protection.
So I hope the Rams go WR -TE or TE-WR, assuming the right fit and value is there.