I would agree with you to an extent. For the greatest straight pool player, I think it's fair to say most with a civil mind would pick Mosconi. I think he was competitively the best, given his tournament and exhibition records.
Having known Babe Cranfield during his very good years, I would say he had more knowledge than any other player, but chose another full time career. I watched him run hundreds and two hundreds every day when he was in his 60s, long after Mosconi did that at an earlier age. How Cranfield would break down a rack was a rare talent.
All the best,
WW