It is a top 5 offense on paper, depending on how you rank them....points, yards or how it should be ranked, how does it perform against the better defenses?
Back in the day, you could predict the teams you wouldn't see in January, they were the fun to watch passing teams in October that usually had the offensive stats at the end of the season. But the stat that would stand out the most was their loss column and how they fared against the better balanced teams.
The Cowboys should have the best offense, they've got the most money allocated to it and 6 first round picks on it. They're the most offense centric team in the league because the GM is a follow the ball fan.
I do think the offense is good enough to win the East with just a partially repaired defense.