Rob, just my guess, but I doubt if the NH engineers happened upon it all, my guess is they just brought it over from Shibura who had been making them that way. Shibura make the Ford CUTs and now makes the Case and NH CUTs. It is likely that NH saw the design on the Shibura tractors, tested it, refined it, and realized they could dramatically improve FEL visibility by using the curved arm design.
The difference between the old Fergusons we see in this thread, and the original Shibura loaders is that the Shiburas had full hydraulics where these all appear to be trip bucket designs on the old Fergies.