Carter actually profiles more like Davis than Trumbo, with more extreme BB% and K% rates than Trumbo. Even in his very bad 2015, Carter posted a wRC+ of 104. Compare that to Trumbo's equally bad 2015, when he posted a wRC+ of 107.
However, Carter rebounded from his poor 2015 campaign to have a solid 2016, posting 41 home runs and a .222/.320/.457 slash line. Nothing groundbreaking by any means, but certainly worth a look if he can put up anything like that in 2017. Carter might have even had more home runs to his name if he was hitting in Camden Yards - check out his 2016 spray chart overlayed on OPACY:
|Source: Baseball Savant, Statcast|
Anecdotally, when a player exhibits a strong three true outcomes profile, he also has platoon splits that show he should only play when matchups are favorable. Carter has hit righties and lefties about equally, so there's no reason to think he should be anything but a full-time player for the Orioles, whether it's at DH, spelling Davis at first, or (gulp) in the outfield.
Carter should be a DH. But since the Orioles appear willing to try and hide a bad fielder with a good bat in the outfield, I should mention that Carter has 549 innings in left field and 17 in right, and he's posted roughly a -30 UZR/150 in both.
I don't put much stock into this because each of these pitchers is good enough to know where to pitch opponents, but the Red Sox' aces, David Price and Chris Sale, each through a number of pitches in the upper right portion of the zone, which is up and away for Carter:
There's no fancy math or stathead secret in play here: Chris Carter is likely to give whichever team signs him the same production that the Orioles will get from Chris Davis and someone will get from Mark Trumbo. Baltimore has already sunk a lot of money into Chris Davis, and is thinking about doing the same with Trumbo. Why spend that cash on a multi-year deal for a flawed right-handed power bat (to be clear, I mean Trumbo) that will carry through what is potentially a mass exodus from Baltimore after 2017? Especially when there's potentially a very cheap one-year deal for essentially the same production sitting right in front of the team.