Well, at least re-using holes is one of the benefits of a flat site, LOL. As TD notes, the absolute best holes come from micro designing a green or feature to a very unique site. But, I am sure Mark and I will never get as many unique sites as TD, and even on gently rolling ground, it's easier to envision some version of past holes if there is nothing unique about the land.
Besides, some architects think in terms of golf shots, and even providing a balance of golf shot types, others in terms of on the ground features, eventually blending both in some form or fashion, but leaning one way or the other. I am sure JN and others thought process includes hitting high fades, low draws, etc. etc. etc., and if a green angled left with a particular approach contour and bunker placement to favor a shot, then it still works elsewhere, providing the wind is similar.
Overall, while fashionable to tell clients that every design is from scratch, we all know that isn't true. Sometimes the question is like songwriting. How many notes have to change to keep My Sweet Lord from being a copy of He's So Fine? Take the green angle as per above, change out a sand hazard for a tree, reshaping the green just a bit to fit in without damaging tree roots, move a bunker somewhere else, have different side slopes because the site is more gentle, and voila, a green very few would notice started out as an idea from somewhere else.
Believe me, I have dropped in past greens in CAD to a new project, and it very rarely fits as is, and usually ends up being more work to tweak it rather than have started almost from scratch.