Essentially, from what I have seen, Madden plays more by the play types called than the actual ratings/skills of the player.
The ratings come into effect when there are direct challenges, jump balls, blocks, tackles, etc. But the play design itself versus the chosen defense and then the decision of where to throw the ball is really what makes everything happen.
I hope that deep blue zones are addressed in the future to make them more usable and modifiable like the other zones. Because as it is right now, there is no need for an Earl Thomas playing the middle 3rd in the Cover 3, for example, because the game won't play out the skill of the player properly because it is play design that dictates the majority of outcomes.