The idea of numerical superiority is nothing new, rather its something we are all familiar with from the time we were young. As children we can all remember being the playground, lunch room, and in class and suddenly hearing those four words , "keep away from ____." Suddenly, two or three friends would join in and the game was on! Weather it was a child's toy, lunch, or pencil, the child would get frustrated and would start crying until the teacher would interfere.
In Soccer numerical superiority is very much the same idea. We try and create different situations where we have more players in one area so that like the children who can hold stole the toy, we too can hold the ball for long period of time. We do this by creating overloads, meaning when we have the ball bringing more players closer to the ball to create this keep away scenario.
Using the same example, this time imagine that the child that stole the toy never got the help of anyone else. Even if the child is bigger and stronger, the job to keep the toy becomes harder. These are similar to situations where we do not have Overloads. When these happen in the game it is much harder for us to keep the ball. Going back to the example of the bully if the bully is stronger and bigger then the child they might still be able to keep the toy. This is like a team full of great technical players which are superior in 1v1 situations. As a result, when we train players we always begin with the harder game situation first. We build players on a foundation of 1v1 greatness and progress to teaching Overloads.