Mactavish was an impending UFA who had 26-32 points (during a much higher scoring era) for 4 seasons prior to getting traded to the Rangers. He shared 3C/4C with Nemchinov, though mostly 3C. We we gave up a kid who went on to play 1,200 NHL regular games and 95 more in the playoffs for 12 regular season games and the playoffs from Mactavish.
Some team may need depth and doesn't want to throw a first+ for a higher end rental.
I think someone would pay a second for Names or at a minimum 3+4. Same for Vesey and Fast. I think they return 2, 2 and 3 (assuming that one has a subpar season). Which is not bad.
Realistically we could be looking at something like 5OA, 18OA (Zuccarello), 22OA (part of the return for Kreider), 2, 2, 2, 3 3, 4, 5, 6, 7, 7, 7. That's a lot of firepower to upgrade the rebuild.