1. Mixing the middle of the field open and closed
When Matt Eberflus was hired, there we clear ties back to Tony Dungy, and thus Love Smith, Monte Kiffin, and the Tampa-2. When you see that Eberflus runs zone more than most, it would appear to many that he is bringing the Cover-2 defense that Smith had in Chicago back.
However, the stats say that he mixes up his coverages rather well. Last year, he ran Middle of the Field open plays, which are Cover-2, Cover-4, and similar coverages on 41.5% of his defensive snaps. He ran middle of the field closed, which means just one high safety on 45.4% of his snaps. Then, 12% of the snaps were either in cover-0 or with other factors.
Either way, this shows that you are not just getting a standard cover-2 defense. On top of the fact that Eberflus brings his defensive line techniques from Rod Marinelli, you can assume that while he does not mix up his blitz, and man coverage, he does mix up what he does.
Four are coming, but angles, stunts, and other variations help mix up and play to the opponent. Beyond that, the backend is tied to the front and can change based on who they play. So, there is truth to the idea that the Bears will be simplistic under Matt Eberflus. However, at the same time that does not mean that they are stale, and it does not mean that they always do the same thing.
How Ebeflus changes these trends based on who is on his roster will also show what type of coach he is.