If you really want to be a Tatum Completeist.. you need a good discography.
Classic while claiming to be complete often have gaps( sometimes quite unexplainably) in their Chronology.
If you have acess to a discography, the Past Perfect Tatum box probably has a lot of early Tatum also. I would expect lots of duplication between the three.
From your comments in the Tatum thread, I can see how you could lean towards being a completist, but suspect the listening experience would be totally overwhelming and possibly bad for your health