If going by yardage, sure.
But based off points, KC (308) was ranked better than Dallas (321) and SF (310).
Then looking at interceptions, KC (16) had over double of Dallas had (7) and had more than SF (12).
And lastly, looking at better against the pass, KC had more sacks (45 to 41), better QB Rating against (80.8 to 91.9), better completion % against (60.5% to 65.0%) and less total passing yards (3,543 to 3,576) even though they were passed against more (582 to 569).
Sure, you could say the Dallas and KC Defenses were similar based off one or two stats. But KC had a better D than Dallas, and it wasn't even close. Hell, in a lot of ways, you could even argue the Chiefs had the better defense in their Super Bowl matchup.