Spuzz other factors to consider as well, were that the tournament schedule was totally different back then, as well as not having anywhere near the money then that they have now in pro golf. Heck, Nicklaus sold insurance in the off season just to feed his family, and he was the best there was back then.
Going back even further, you have to consider Walter Hagen, Byron Nelson and Ben Hogan in all of this. Sam Snead anyone? Heck, Bobby Jones won 13 majors in his time, including the calendar year Grand Slam as an amateur. Is that even possible now, having an amateur be ranked #1?