To qualify for any MLB leaderboards a pitcher needs 162 innings and a hitter needs 502 PAs.
Baldwin is at 401 PAs, or ~80% towards being qualified.
Horton is at 115 innings, or ~71% towards being qualified.
Voters have historically favored RoY players who have played a full season if things are close, but neither player is going to qualify for any leaderboards, so it's a tough argument to make in Baldwin's favor.
Having said that, I still give the award to the catcher who's been in MLB since opening day over the SP who can't strike anyone out. However, if Baldwin keeps backsliding for the next 2 weeks he won't deserve it. His .506 OPS this month has really hurt his chances.