One resort in Michigan I visited had 3-4 courses. The newer ones were cartball courses with fantastic viewers, forced carries and awkward land.
The original course was 6300 yards and a good if not great golden age layout by Bill Diddell if memory serves. It had wonderful undulating land, interesting greens and was both playable and interesting for all.
My visit was about ten years ago. At least in those tough economic times, the original course offered foot golf with giant holes cut in the greens to accommodate soccer balls. There were not many people playing golf or foot golf at the height of summer. The others were packed with carts.
Maybe the owners knew what they were doing with the other courses. I am not sure I am the best judge of what type of design serves resort clients the best.
I believe the resort you are talking about is Shanty Creek. The Bill Diddel course is The Summit. It was the original resort at the course. They have the original course layout in the basement. The back 9 has been altered significantly and those greens (at least the newer ones) are not as good as the front 9. The original holes / greens are some of the best in northern Michigan. I have sought out older Diddel courses as a result of playing The Summit and have not been disappointed.
Chris