True story: At a very high end development, a "signature" course was constructed to "exact" USGA specs with attention to detail at every layer: gravel, sand, etc.
However, the gravel was not washed because somehow that requirement got deleted in the final contract. Here were greens being built with gravel covered with dusty silt. It is still there, mucking up the bottom layers. How long will it last? Who knows. But, it goes to show that complexity does not always translate to better and more improved. In this case, pure sand would have been a better, cheaper and easier method. As it stands the green is likely a hodge-podge of materials as a result of the layers and the intrusion of "who-knows" how much fines and silts that have migrated down to the floor.