Let's just say they trade for Robinson, and still the season is garbage and Sam looks awful. They are still in position to draft Lawrence, and he comes in with an OL already in the process of being rebuilt with Allen Robinson, Jamison Crowder, Chris Herndon, and Ryan Griffin to throw to. Nevermind Mims, Smith, and whoever else might be drafted/acquired.
Let's just keep hoarding cap space and draft picks though
That's the thing, I don't think we are. the margin for error between picking #1 and picking #3 is very small. It's not uncommon to have 2 2-14 teams in a single year. Adding Allen Robinson IMO takes us from a 2-4 win team to a 4-6 win team.
So if JD makes that move (assuming its both possible and reasonable) then he is committing to NOT picking #1 and as such is saying Sam is our guy. You can't pick #2 and get Lawrence, and there are only about 5 teams in the league who if they found themselves at #1 wouldn't pick him and those are teams with all star QBs who are under 30 (Mahomes, Jackson, Wilson, Watson etc). Most of that group either doesn't have a 1st round pick, or has already won enough games to assume they won't lose out to get to 2-14/3-13. My point is that no one is coming off the pick to take Lawrence, so if you want him, you have to be bad enough to 'earn' him. Allen Robinson is probably enough (barring injury to Robinson or Sam) to keep us from being that bad, but not bad enough not to pick top 7.
If JD isn't 100% sure Sam is the guy I don't think he can make that move right now. Now if come Halloween, Robinson is still on the market and we have already won 2-3 games and don't appear that we can get the #1 overall pick by just flat out sucking, then we are talking about a completely different situation. Saving Sam becomes the only logical play, and going after Robinson suddenly makes so much more sense.