So what are the coaches supposed to do? Build a scheme to fit around each individual player? How is a coach supposed to build a scheme that's tailored to all five players on the back end? Assuming you're going with three corners and two safeties. Coaches draft & sign players that fit their scheme because you cannot Tailor a scheme to fit five different individual play styles. You get the players that you feel will compliment each other and form a cohesive unit. A group working together as a whole toward a common goal, is far more effective than a collection of egos that are doing their own thing. That's one of the very first lessons of organized sports. If you play ball, you learn this right from the start. You don't actually play ball.