I feel like a broken record this afternoon, but that is really oversimplifying things.
1) To get a compensatory pick that's better than the 15th-21st pick in the 4th round, the Packers would have to get a pick in the 3rd. The guy who leaves has to get a really big contract to merit a 3rd round pick. In this last draft, there were four handed out.
Arizona got one because Calais Campbell got 4/60/30
Houston got one because A.J. Bouye got 5/67.5/26
Denver got one because Russell Okung got 4/53/25
Cincinnati got one because Kevin Zeitler got 5/60/31.5
So the average of the four top contracts that received 3rd round picks comes in at 13.4M. Clinton-Dix is more likely getting a deal in the 8-10M range. So he would probably bring a 4th, maybe a 5th if the market for safeties stays cold, in 2020, if...
2) To get a strong comp. pick for Haha, Gutekunst would have to stay relatively quiet on the open market. If he were to sign a replacement safety or an edge rusher to similar money, or more, Haha would be cancelled out and they wouldn't be in line for said pick. I thought the whole reason Packers fans were excited about Gute is that he will be more active in free agency.