I found it very easy to identify who the designer was on most of those images just from the look and comparing it to their other work. I find this intereting given that the designers "swapped" some holes to make the final 36 work as 2 x 18.
13 Blue appealed to me. How long is that hole, I assume it is drivable in some conditions.
Just nitpicking here, but I do not believe Mr. Doak said they swapped holes, per se.
I think each firm designed and built their own 18
What Tom did say is through the design and routing process, some of the "holes" Mr. Coore discovered and proposed utilizing to build his course, ended up being used on the Doak course. I can well imagine some of the basics of those holes---such as whether it is/was a par 3, 4 or 5, and maybe even which way it doglegs, where a nice big sand blow out would/could be utilized as a bunker, etc. is featured and WOULD HAVE been featured on a hole designed and built by either group.
But I am pretty sure each group built their own course.
Tom said the original plan was 18 holes, but they found enough good land for 36.
36 holes in the sandy blowout dunesy land was only going to work, routing wise, however, if they sequenced the holes in some semblance of a fashion where green to tee traffic made sense.
I'm also sure nobody wanted a course with a bunch of par 5s and par 3s in a row or an "unbalanced" course.
So, long story short, it was through the process of making 36 work on the site, that some original parcels of land Mr. Coore thought would be well-suited to his golf course, ended up being utilized, designed upon and constructed, by Mr. Doak.