Let’s say Sandin is really nice and takes 1.5m aav… and let’s say some nice team comes along and hands us a 3rd for Kerfoot… we are still around 400,000 away from being over the cap. Which team is in a tougher spot? I can only think of Vegas

Smith looked very good. Smart, tenacious player. It's not like he's been toiling away in the minors and never got a call up. He just exited college. Had 19-31-50 in 36 games for a D1 school. Bobby Brink was the only higher scorer in NCAA D1 (14-41-52 in 39 games).
I think he's already looked fine as a 3C. I don't know that his ceiling is much higher a middle-six option, but I definitely wouldn't trade him for a third.

I like Sandin quite a bit, and he'd probably get more minutes with the Coyotes, but I'm not sure the Coyotes make that move with the logjam at D for the moment and the thin forward corps until the recent are ready to push for a roster spot. Maccelli and Smith fill a bigger hole for the team, imo. Depending on what they get back from Chychrun and Ghost trades eventually, maybe that changes.

Smith looked "fine" as a 3C for all of 10 meaningless games playing for a bottom feeder. On any somewhat decent team, he's a depth piece. On a contender, he may never see the NHL ice.

Sandin has yet to sign but if he is signed for 2m let's say, where is he playing? Either Muzzin or Holl got to go. Holl is the easier to move, so perhaps Giordano will play the right side. They still have the option of trading Sandin himself as well for RD for a cost controlled RD who is actually an NHLer.

It's a signing and 2 trades at the most. Not to mention that they could waive guys like Jordie Benn, Wayne Simmonds, Kyle Clifford and maybe even Adam Gaudette without them being claimed. The minimum roster is 21.