Patrick,
I am hardly a local boy in Monterey, and am not really a go-to-guy when it comes to things MacKenzie.
There are some very able researchers who have looked extensively into MacKenzie's life in general, and his work in Northern California, in particular. They are the "go to" guys on this stuff. Hopefully, if they have not been mortally insulted by your Hollins thread, they might chime in here. Or, they might just tell you to pound sand. Beautiful, wind-blown sand, like the dunes at Cypress.
As for me, I have managed to stumble into a few interesting tidbits here and there, and they might have some bearing on the discussion . . .
So far as I can tell there was a routing (or at least a partial routing) in place prior to MacKenzie's direct involvement in the project. The legend of Miss Hollins at the 16th suggests it, as does a different CPC legend. That and a timeline.
We've probably all heard of how Hollins and Mackenzie wanted at tee out on the rocks behind the current 18th tee? There is even a plan for the bridge in Geoff Shackelford's excellent book on CPC. Also, here is a photo of the proposed tee location from Golf Illustrated . . .
The caption mentions that "A golf architect has just erected a little marker . . . " and the marker or stake is visible on top of the large rock on the right side of the photo. Pretty cool, huh? Here is the rub . . .
This photo appeared in the December 1925 edition of Golf Illustrated. But according to Sean Tully, Neil Crafter, and the able researchers who have looked into it, Dr. Mackenzie did not arrive in the U.S. until January 20, 1926, was not on the West Coast until about a week later, and did not receive the Cypress commission until February 1926. (Raynor had died in January 1926.) So it was seems rather unlikely that Mackenzie placed the stake for the tee.
Does this means that Raynor had staked out this tee and/or the rest of the course? Not necessarily. There were other talented people around, including Hollins and Hunter. That said, Raynor may be the most likely suspect, given that he had reportedly been hired to do it, and given his work on the Peninsula up to that point. Whoever placed the stake, it wasn't Mackenzie unless he literally mailed or phoned it in.
Another interesting tidbit is from W.D. Richardson's brief obituary in the Metropolitan Musings column, American Golfer, March 1926:
His work will be carried on by Charles H. Banks, his associate. The layouts on which they were at work when Mr. Raynor died are W. K Vanderbilt's Deepdale course at Great Neck, Long Island; Cypress Point in California; the Honolulu course in Hawaii; Rock Spring at Orange, New Jersey; Lookout Mountain in Tennessee; Statesville in North Carolina; Yeaman's Hall at Charleston, South Carolina; and the Blue Mound Country Club at Milwaukee.
Maybe W.D. Richardson meant MPCC? That seems a stretch, but who knows?
Anyway, as I said, these are far from definitive answers, but they are probably worth keeping in mind.