Matthew,
Nicklaus has one course in Golf Magainze's top 25 worldwide, and two in the top 50. BTW, your definition of great is very narrow. There are probably in excess of 30,000 courses worlwide. 1% is an arbitrary number, probably way too low in most any other context of what constitutes greatness, but it fits my definition. I have no desire to go tit for tat, but I think that most people who don't have an ax to grind on the classic vs. modern argument would agree that Jack's work is disproportionately represented in this broader category of
"great".
BTW, borrowing from my friend Matt Ward, how many Nicklaus courses have you and Chris played? I've played a fairly good sample and have yet to find a dud. But, oops, I forgot. To some here, experience really doesn't matter when it comes to evaluating gca. Hopefully, you are not of that persuasion.