This system, as simple as it is, has proven to be one of the most effective systems for distinguishing & communicating your defenses zone drops.
You have to get the best 11 defensive players on the field to be successful. Teaching coverages by concepts allows you to plug in the best available player.
From FBS all the way to High School, there are times when you are limited in your schemes based on your personnel. Provide your players with a toolbox of schemes, including quarters coverage, they can use to put themselves in the best position possible based upon their skills and the skills of their opponent.