Eck:
I submit that if you were starting a franchise with any one pitcher from ML history, knowing exactly what path their career would take, there are many guys you'd pick before Koufax.
Your point is a good one for the "best ever" argument, but for the "is he deserving?" argument, consider that if we're starting say 30 franchises, is Koufax the #1 pitcher for one of those teams? I think so.
Just for fun, let me add, if I'm starting that franchise today, I want guys who are going to excel for me, not for the Yankees/Mets/Red Sox/Dodgers once they hit free agency. Koufax suddenly looks a lot better, with his performance from age 25-30, cause its likely going to be for my team