There-in lies the rub. Although Nunez has looked surprisingly okay at 3B this year, he's not remarkably better on defense than Devers or Holt at 3B.
Devers might make a few more plays than both of them, but he also makes unforced errors at a shocking rate, and those seem to be seared in everyone's minds- fair or unfairly. JD should DH, so it comes down to Devers vs Nunez or Holt at 3B. I suppose we could take Lin over Vazquez or Swihart, but Vaz has been the personal caddy to a couple starters all year, and Swihart gives us the ability to PH for our weak-hitting catcher 1-2 times each game.
(We should be fooled by Lin's recent hitting, either.)