Niall
Sorry, I just do not rate Ross, nor the Foulis Brothers.
I would go with Allan Robertson, Old Tom, Willie Fernie, Simpson, Charlie Hunter then Sutherland and Campbell, to cut that down I suspect Campbell and Sutherland would be the first two out.
To be the best does not always equate into producing the most.
As for your comment about Old Tom kicking things off, sorry you are wrong in truth it was Allan, he produced with Tom Morris his assistant the first of what we call designed courses. As for Old Tom's courses standing the test of time much must been laid with James Braid plans as many of his modifications of the earlier courses left many Old Tom Holes, Greens and Fairways more or less
intact. His opinion was if the Holes is a good one, leave it.
If the 19th Century designs where limited why did templates ever get exported in the later years of 19th & 20th Century. In fact they still to this day, we are using templates that owe their designs to the 19th Century.
Melvyn
Niall David's list includes The Castle Courses at St Andrews, that alone drops him well down my list for that gherkin of a course or should I have called it Disneyland Roller Coaster or even Helter Skelter.