Those teams aren't symmetrical though. The Chiefs have the best offense and a slightly above average defense. The Pats have a good defense and a well below average offense. At a glance on this chart maybe they seem similar, but it's misleading.

Just look at their season point differential. The Pats scored 17 more points than they allowed for the whole season. The Chiefs scored 127. Regardless of their offensive/defensive ranks, it's very clear from those numbers that the Pats are a middling team and the Chiefs are great team.