Tom, Not to turn this thread in another direction, but you wrote, "All three of those courses came in sort of simultaneously in the late 1920s (1926-1929) so it's sort of hard to tell which one when out to contract first. We do know Aronimink was under construction as early as 1927, perhaps even late 1926 (aerials show that)."
I thought that move occurred in 1922/23. The reason I believe this to be so, and I could be way off base since I'm depending on memory rather than looking in my files, is that Tilly opened his Aronimink course in rexel Hill in 1915 & I believe it was only 6-7 years later when the Ross course was opened and Tilly's went extinct.