Sean,
Most of MacKenzie's work in America was 1929 or later, hence I don't believe that Ross copied his bunker design style in America.
Patrick,
The majority of MacKenzie's work in North America was not done post 1928, it was actually a pretty even split. This list is based on dates of construction.
PRE 1929:
MPCC Dunes, Pebble 8 & 13, Cypress, Meadow, Redlands, Melrose, California, Lake Merced, Valley, Pasatiempo
POST 1928:
Union League, Claremont, Ohio State Scarlet & Gray, Crystal Downs, Michigan, Sharp Park, Bayside, Augusta, Sacramento
There may be no evidence that Ross copied MacKenzie's bunker style, but surely he was aware of it, as well as some of the other prominent Architects that were working out West. And he was certainly familiar with George Thomas' book. Any honest architect of any specialty will attest that exposure to previously unfamiliar styles has an affect on you, either consciously or subconsciously.
Sean,
Great post! I'd be very interested to hear from you and some of the other supers on the board about how their current labor breakdown compares with the numbers on the Golfdom cover -- perhaps a good discussion for a different thread.