I think Gans could arguably be ranked at #1, but personally I'd have a few in front of him. I'd maybe rate him as high as top 4 at LIGHTWEIGHT. P4p I'd put Robinson, Louis, Armstrong, Dempsey, Langford, Attell, B. Leonard, Pep, Walker, Charles, Marciano, Ross, Canzoneri and others ahead of him.
Any post that doesn't have Harry Greb as amongst the elite P4P fighters, is not a serious post ! In chronological order : Fitz, Barbados Joe Walcott, Sam Langford, Harry Greb, Mickey Walker, Joe Louis...I pick the Iron City Express, No.1....
Do you actually feel Walker, as tough as he was, deserves mention in the rare air of these men? I put him half a step below but obviously still great.