Another good example of building a course over an existing layout is CommonGround near Denver, which was built over the existing (and forgettable) Mira Vista golf course. I have some vague memory that Tom Doak and team routed a number of holes in the areas that had been between the old existing holes, which I thought was an interesting idea.
There is one spot in particular where trees were planted tight on either side of a fairway so that the clearing was only about 100 feet wide . . . and then in the gap from there to the next hole the clearing was 200 feet wide . . . so we moved the hole into the wider clearing! Luckily, there were only a few holes with rows of trees planted around them; the site was pretty open.
I never actually walked Mira Vista, the only time I saw it before construction there was an inch or two of snow. But my associates had spent a lot of time there, and didn't want to preserve much of anything, so I just worked on the routing from a topo map paying no attention to where the holes had been.