I am telling you, that when you start a franchise, it is a fantasy world. If the world IRL thinks that X player is only going to produce with a C potential then EA has to make his potential a C until he proves otherwise IRL. Just because you put him in a situation where he can produce numbers that seem high for his overall doesnt mean he is any better IRL or in the game.
There is no way to make Bradys with this years rookies under this system unless there is a roster update. But it is the closest representation to what happens in the real world and that is why it is best.