No way. An average offensive attack will allow much more leeway than a top 5 defense. Look at the playoff teams from year to year. I've seen this data compiled. If your offense is ~15 and that team was successful most of the time the D was in the top 5 or close. Maybe top 10 but then you're starting to push it and the chances of playoffs drops significantly. If the Bears are 15th in offense and 8th in defense, I have a hard time thinking they won't be able to "make some noise". They were 15th in offense and 5th in defense in 2006 and were the best team in the NFC. Arizona had an average offense and average defense and won 10 games + their division. They can't get away with below average on either side, since they aren't likely to be good enough on the other to make up for it. But an average offense and an above average defense will give them a shot and doing good things, especially with top special teams. Well, don't run off with "making noise" I'm saying getting to the playoffs and winning games. Being a playoff team and then being successful, not winning lackluster divisions. And the 2006 Bears prove my point to a tee. If you have one average unit, you generally need a top 5 or close as the other. Not taking into account special teams. There are many other examples of this outside of the 2006 Bears. Also, hovering in the Top 10 in both units are also consistently successful in the playoffs. If the Bears are 15th in offense and 8th in defense then they certainly have a shot but generally one of those units need to be elite, or both above average to set yourself apart. They might sneak in the playoffs but won't get very far barring some luck.