If we look at passing, rushing and receiving stats, only 3 teams in the playoffs have above average offensive and defensive rankings.
Pittsburgh
Offensive rank average: 11
Defensive rank average: 3.33
Houston
Offensive rank average: 12.67
Defensive rank average: 3.33
Atlanta
Offensive rank average: 11
Defensive rank average: 15.67
We can see here that Pittsburgh has the edge in both offense and defense.
Lets look at some other teams.
New Orleans
Offensive rank average: 2.67
Defensive rank average: 23.67
See the problem? Bad balance. Fantastic offense, lousy defense.
New England
Offensive rank average: 8
Defensive rank average: 26.33
Same story as New Orleans. Out of balance.
Green Bay
Offensive rank average: 11
Defensive rank average: 26
Same story, and Pittsburgh still with the edge defensively.
Baltimore
Offensive rank average: 16
Defensive rank average: 4
All teams aside from Pittsburgh, Houston and Atlanta are significantly out of balance. Pittsburgh has the edge.