To offer a contrary note, I make 2 observations:
1. Oakmont; having been born, grown up, went to school, now live, in various parts of the eastern US, I find the tree-less landscape jarring and un-natural. A few specimens in very infrequent intervals and numbers, in my very unlearned opinion, would make the course-landscape seem more in place. Trees are a part of the eastern US.
2. The course I know best, Riverfront ... Some planting in some clusters on the perimeters of various holes would help soften the impact of the development.