Of course Denver has the harder schedule, not really all that surprising when you think about it.
Denver has to play the 14-3 Chiefs twice. So that counts for 28-6 on their total.
KC has to play the 5-12 Broncos twice. So that counts for 10-24 on their total.
That's an 18 game differential that has to be made up for on the 3 teams they do not play in common.