Cruz on a one-year deal would be a strong fit for the Mets, with prospect like Mark Vientos potentially ready to debut at some point this season.
Vientos can play third base and got a taste of left field last season, but it's possible he ends up as a DH in the long run.
If the Mets are going to sign another big bat this winter, it makes sense for it to be someone like Cruz on a one-year deal to DH or a more versatile player -- like Kris Bryant -- on a long-term deal.
Dedicating big years and dollars to a player like Kyle Schwarber, who is basically a DH only because of his defensive limitations, would make little sense.
Verdict
If the Mets are making one more big splash and Cruz is open to a one-year deal, he should be their target.
Signing Cruz would allow the Mets to deal Davis and perhaps Smith, while possibly bringing back starting pitching in return.
If the Mets don't add a DH from outside the organization, turning to a group including Smith, Davis, possibly Cano, and eventually Vientos to fill that slot would be just fine.