Where would Devers play if not 3rd base? I suggested earlier him to DH and Yoshida to LF but Yoshida seems to be a bad fielder himself. Trading Casas (LHB) for a need like pitching, catching, RHB seems like a good idea, putting Devers on 1st. Our offense was pretty effective without him.
Not signing O'Neill and Anthony also being LHB, makes it even more of a good idea. Pete Alonso came to mind as an off-season acquisition. Hes a RHB and Devers needs home run protection at the plate, though not exactly Big Papi, Manny combo.