There’s a value added to the overall defense, even if you have just two different versions of “bad”.Ultimately, the quality of the commitment and ability of the defenders matters more that the type of defense. Bad man-to-man defenders make bad zone defenders.
In baseball, you’re a better pitcher if you have a bad fastball AND a bad change-up than if you just have a bad fastball.
Anding a different schematic really matters. And it probably helps improve the defenders timing and instincts.