Several thoughts, shooting from the hip:
1. "Better" topography, in this case, means more elevation change, doesn't it?
2. With elevation change comes not only high spots, but low spots, and therefore less uniform drainage.
3. I'm no expert, but I find it difficult to put much stock in a huge difference in the amount of clay under #4 vs. #2; there are courses a lot farther away that are clearly sand-based in that area. But maybe?
4. Most importantly, I'd suggest that nobody draw ANY conclusions about much of anything having to do with drainage in NC right now. Since the beginning of September, there have been two hurricanes (one of which was historic and dumped 30" of rain on the Sandhills) a tropical storm, and an epic early December storm that left a FOOT of snow just slightly north of the Sandhills. Courses in Piedmont NC are wetter than I've ever seen them, and I've seen them for a LONG time. We all know the miracle of sand-based drainage, but this has just been ridiculous. Wilmington surpassed 100 inches of rain in 2018, and surpassed it's average yearly rainfall July BEFORE Florence even hit; the year's rainfall was nearly double the average, and almost 20" above the previous record. And there has been no letup in precipitation since the beginning of September, right up until now. I've just never seen anything like it, and I've seen sand-based courses in this period of time that have just been bogs.