Jason, I would generally agree with your assessment on those rankings. I am not highly familiar with the Doak scale (haven't read the book), but it would seem that by that name, we should only allow him to use it. Otherwise it is a subjective scale and it might as well be a Warren 6 in that case.
As for the courses, you are probably right about the 4's, I haven't been to Idle Hour, but imagine from the select few I know that have played it, it would have to be at the very least a 6. I haven't been to Olde Stone either, but many whom I trust have seemed to enjoy it and are of the opinion that it certainly is a better, more interesting golf course than Valhalla. I certainly enjoyed Valhalla, but can understand also that it is not among the greats and highest rated on his scale. I would be interested to hear Tom elaborate on why he knocks Valhalla down below 6.