I'll let Mike address your latest post TMac (gosh I so look forward to more of your constructive criticism).
I believe Tom MacWood is really confusing the site selection and routing of the golf course between spring 1913 to April 1915 from the physical construction and subsequent grow-in which began April 1915 and ended with the course opening in late May 1916.
I think sometime after the course was routed and construction began guys like Crump became less involved, and I think most of the construction effort was led by Wilson, Smith, and Klauder, with Flynn shaping. I also think Meehan was probably as much a grass guy as anything at that time.
MacWood's selective use of a few articles to drive an agenda instead of trying to understand all of them in total is really poor analysis in my opinion. He really seems to have no idea how collaborative efforts worked, but instead is so focused on naming "the architect" that evidence outside of that knee-jerk predisposition of his either gets ignored or purposefully re-cast as something it's not.
In this case, I think that MacWood won't acknowledge that Crump was part of the design team whose involvement probably levelled off once construction started simply because he's spent years trying to tell everyone that Crump only constructed to other's plans, and wasn't a designer in his own right. That would fly in the face of Joe Dey's statement that all of the men on the committee were picked for their previous design and construction experience, but he'll just ignore Dey and say the article was written years later.
Here again are the contemporaneous materials about Crump (and others) as provided on the other thread...
In spring of 1913, shortly after the Merion East course opened for play the previous autumn, but while Merion West is still under construction, Robert Lesley names a committee of experienced men to search Fairmount Park in Philadelphia to find a place for a public course. Later in spring 1913 this group recommends a site in Cobb's Creek park;
Once the site for the course is located, we see that "experts" in course design and construction will be responsible for the golf course. This group has a routing plan together by the spring of 1914, which gets approved by April 1915.
From the actual Golf Association of Philadelphia (GAP) meeting minutes of January 1915, we learn of the group members. Ironically, Hugh Wilson's name is somehow omitted here, although it does appear in many other news reports, as well as in other GAP meeting minutes.
Shortly before the course opened, this article again lists the members of the committee appointed by Lesley, giving Hugh Wilson credit for drawing the first "tentative" plans for the course which we know went through a number of revisions;
An article by "Joe Bunker" about changes to Philmont Country Club (which Hugh Wilson was responsible for) again lists some of the "experts" who were responsible for Cobb's Creek. The person in question was Ellis Gimbel of Philmont.
And, most ironically perhaps, given the acrimonious, personality-based rancor exhibited here recently,
The following 1928 article by Joe Dey, former head of the USGA, addresses both the men responsible for Cobb's Creek, the reason they were selected for the job, as well as the number of rounds played there up until that point, all found by Joe Bausch in the Philadelphia Golfer Magazine and posted in part in another recent thread by Indiana Joe(nes);
I would also point out that there are not one, but two articles indicating that Walter Travis had been spending time helping out at Cobb's Creek, and both are seen on page 63 of the book. The first mentions that, "most of his (Travis) time has been given to assisting in the laying out of public and others courses such as Cobb's Creek and Halloween Park and Pine Valley." The second, from January 1916 in the Philadelphia Inquirer states:
"Walter J. Travis has spent a good deal of time lately in making suggestions as to notable public courses, especially at Cobb's Creek and Halloween Park, Stamford. It will be recalled that the late Mayor Gaynor, of New York , drafted him two or three times in a like capacity for Metropolitan courses.”
Later I wrote;
"From the descriptions of Travis’s involvement at Cobb’s Creek from December 1915 and January 1916, it’s difficult to tell exactly what architectural work he did. We do know that the routing of the course was completed as early in April 1915, and built along those lines. We also know, however, that the course was originally scheduled to open in September 1915, and that by December, Travis is described as spending “most of his time assisting with the laying out of…Cobb’s Creek…” One could reasonably imagine that at this point, the local “experts” were only to happy to have Travis and his expertise onsite to help with both agronomic and drainage issues, as well as the possible finalizing of design features such as internal green details and other earthmoving details."
Now, I have to laugh when I consider that in other select cases a few here have argued that when a group of novices brought in an expert like Travis for advice, that would lead a select few here to want to give Travis sole design credit! 
Here, the book just notes that he was involved in the project in its later stages of construction. 'Nuff said. In the case of George Thomas, no one is saying he designed Cobb's Creek, or that he was part of the committee that did. However, we did think his onsite time amounted to a mention, particularly since Thomas himself said he learned a great deal from Hugh Wilson by watching him at Merion and Cobb's Creek. Here is what I wrote in that regard;
"It also seems that Thomas spent a good deal of time at Cobb’s Creek with Hugh Wilson. Geoff Shackelford, who wrote the definitive biography of Thomas, “The Captain”, writes; “Thomas spent considerable time studying Hugh Wilson’s work during the construction of Merion Cricket Club’s East Course in 1912, its West Course in 1914, and at a municipal course in Philadelphia , now Cobb’s Creek.”
"Thomas himself wrote, “I always considered Hugh Wilson of Merion , Pennsylvania as one of the best of our golf architects, professional or amateur (note the early need for distinction). He taught me many things at Merion and the Philadelphia Municipal (Cobb’s Creek) and when I was building my first California courses, he kindly advised me by letter when I wrote him concerning them.”..."
Then, given that Thomas had already done some limited design work of his own at that point at Marion (MA), Whitemarsh Valley, and Spring Lake, I surmised;
"...We also know that like other members of the “ Philadelphia School ”, George Thomas was a “naturalist”, whose own design work in California set new standards for blending the hand of man into the native environment. While we will likely never know the extent of Thomas’s actual input to the final design of Cobb’s Creek, it seems likely that his opinion was sought, valued, and considered by Hugh Wilson and his other friends in the Philadelphia School who collaboratively designed the course. It also seems that he spent a good deal of time there and that he considered it time well spent furthering his education in golf course architecture."
The book also contains a lot of information detailing William Flynn's role as the lead shaper, but one article notes that he made a trip to New England to study the famous courses there looking for ideas to bring to the Cobb's project.
And finally, I'm not sure if there's a reading comprehension problem among some, but the Opening Day article in the book not only calls Ben Sayers, "The Instructor" in the caption of a photo, but also states, ""Benny" Sayers, the professional, who will have charge of instruction...". We don't know how long Mr. Sayers acted in this role. Horace Gamble became the pro for many years around the same time.