identical (slight nod to Greinke), but Arrieta has more CG, wins, and SO. Plus he had the single best second half in MLB history. 20 consecutive QS, 16-1 in that time (only loss was to Cole Hammels who threw a no hitter in the game), 0.7 ERA in second half, etc.
They both deserve it, so whoever doesn't get it will have a legit complaint.