Thirty-two teams ranging from 91 to 72. Eight teams are above 85, three are above 90, three teams are below 75, while the median team rating is around 80.
The Cowboys are ranked 15th with an 81. Welcome to the middle of the road, Jerry.
Below are all 32 NFL teams, ranked, based on their Madden 15 OVR rating, including the justification for the ranking my EA Sports rating czar Donny Moore. The game itself is out August 26th (you can reserve copies here).