They don't though. It's strictly a "Who has the biggest stats" award.
For me, Allen and Mahomes are such a large portion of why the Bills and Chiefs are so successful, they are really the only candidates for me. If anything, Allen should be the front runner based on what he means to the offense. Out of the Bills, Chiefs and Eagles.....Bills suffer extraordinarily if Allen is out. Which is case enough for me for Allen to win MVP. But I don't vote so, moot point.