Mike-
Your "distinctiveness" thesis is unraveling like a cheap suit. To wit, you site Scotland Run's use of a sand quarry as distinctive. Perhaps you've forgotten that Merion and Manufacturer's, just to name a couple, incorporated sand quarries in their routings - in both cases, many decades before Scotland Run. Even Black Diamond Ranch in Florida famously incorporated a quarry, and that too was buildt two decades before Scotland Run. You go on to site Twisted Dune's distinctive use of artificial dunes utilizing sand recovered from a dredging. Here too, you seem to have forgotten Whistling Straits, buildt long before Twisted Dune, and the more recent Bayonne Golf Club, both of which incorporate artificial dunes and sand recovered from a dredging.
Are you seriously putting Scotland Run, Twisted Dune, and Glen Mills in the same category as NGLA, Yale, Myopia Hunt, and Plainfield?
Jim