Exactly! Porto know how to replace players. Their club is like a snake shedding its skin. When the old skin is gone, they instantly produce a new one. In other words, when big name players get removed from their squad, they are immediately replaces with younger players, and they are moulded into their team to be made into bigger names. I know that Alex (BlueLion) follows Lyon partially, and a couple years ago, he touched on the fact that Lyon have a very similar policy to this. Their youth setup is immaculate. With developing the likes of Benzema, Gassama, Sissokho, etc.