I can see wanting to give Dwight Smith more of a look. He's in his second full season of MLB and there's a chance he could improve at the plate enough to be a reasonable DH option.
But Chris Davis is just a disaster. He can't even play average defense anymore and his bat is the same limp noodle it's been for the last 2+ seasons. There is no justification for keeping him on the roster and in the lineup at Mountcastle's expense.