I don't think it's unreasonable to think the Penguins could be offering Galchenyuk, Hallander and a 1st that right now. That's basically what they traded for Brassard in 2018 and I feel like Brassard then and Zucker now are fairly comparable in value.
I do agree that I struggle to see teams offering more than that for Zucker, though. We have a pretty good sample size of wingers with term like Zucker being traded and it's usually not for more than that. Whether it's Tatar, Schenn, Hoffman, Johansson or Perron, all of who were similar wingers to Zucker with term that were traded for futures heavy returns, none of them brought back more than the value of a 1st, 2nd and 3rd. Kessel's really the only winger with term I can find since 2015 that brought back more than a 1st, 2nd and 3rd, and Zucker is no Phil Kessel.
You may get a return that fills a need better, but I really doubt the Wild will be getting better offers in value than Galchenyuk, Hallander and a 1st. Seeing how teams aren't as jaded on Galchenyuk as I expected them to be (recent Athletic article from Dutaschek said that most people he's talked to are lukewarm on Galchenyuk, not down on him like I expected), that's probably more than a 1st, 2nd and 3rd in value and that's basically the best return of comparable wingers to Zucker than I can find.