I long ago came to the conclusion that it will always be a matter of opinion. In the end, Merion will credit Wilson, perhaps with a Roger Maris asterisk, but there is some reason to at least consider more deeply the role played by MacDonald in routing and initial hole design for those who want to know "the rest of the story."
I say that because of a few reasons. For one, Merion has acknowledged and the record shows that CBM reviewed and in the words of Mike Cirba, approved one of the five plans under consideration. If they waited for his approval, then he was pretty signifigant in the process whether he did the routings work or merely tweaked it and approved it, no?
Consider three possible non Merion attribution scenarios -
Jim Urbina doing five routings while Tom Doak is on another project. Doak comes back, reviews the five and selects one. Doak gets the credit. Or Jim Lipe doing routings for Jack and Jack having final say. JN gets the credit.
However, at Old Mac, he chose to let Jim be co-designer and get have some of the well deserved co-design credit.
Thirdly, the owner of Tidewater has Rees Jones do a preliminary routing and then runs with it and takes the credit, but later, word leaks out that Rees really did the heavy lifting, despite the owner taking credit.
In each case, there were more than one person working on the project in different ways, but the idea of who gets the credit was decided in everyone's (well, perhaps not Rees!) mind before the project began, and in public, that attribution is unlikely to change, unless Doak/Nicklaus, Doak and the Owner decides it should change.
That is why DM fights such an uphill battle here - as far as we can tell, no one at Merion wants to buy into a different version of their history, much like you would not like to find out that your dear old uncle was really Mom's lover, or something like that! You grew up with a certain vision on life that comforts you, which is perfectly understandable.
That said, I can follow his logic, even if the documents don't conclusively prove that the land swap took place earlier than the meeting minutes show. He needs just a few more documents to make his case, but he doesn't have them, and maybe they don't exist. And, to believe his version, we have to believe that the April meeting resolutions were simply cleaning up several events that happened months before, which is not implausible either. The simplest explanation of why that triangle was on the Nov 10, 1910 plan was that it was under consideration for the golf course in some fashion at that time. The second simplest explanation is that the line was supposed to have been cut off at the college property and was swapped later.
I will say that there is a greater likelihood that any newfound documents would show that CBM was MORE involved than would show he was less involved than currently believed, rather than less, given we can't "take off the table" the visits and reports already known about. However, I was wrong about the first CBM letter to Lloyd, which talked only about soil and I could be wrong about this. Its quite possible that someone could find the original notes of the Merion minutes credting him and find that cooler heads struck out the end of the sentence "We are grateful for CBM's help, but he is such a windbag, we can't take him anymore!"
So, there is the Cliff notes version (appropriate, since this whole thing has gone over the Cliff) - It will always be a matter of (strong) opinion or interpretation, no matter how many more facts about Merion's legacy surface. And, with Mike Cirba showing more and more old photos of Merion in the early years, it is pretty clear that Wilson and others continued to make changes in the early years and that his "legend" is justified from the feature design evolution alone, because even if they started with many CBM templates, it seems clear that they wanted to generally go a different direction (and buckding old CB couldn't have been easy). With enough photos, THAT would be an interesting examination in how one of America's great courses truly came to be great. And, it might even have further applications to gca in general about how to create a great course!