Why not evidence ? An easy evidence is his very few achievement of trophy that can be understand he would have had a hard time to win any World player of the year award in case it was existing. Matthews in the 2nd half 1940s is inferior to V.Mazzola as he didn't win any trophy. For the 1st half 1950s, there were too many top legends for him to beat, Puskas, Di Stefano, Kocsis, Liedholm, Nordahl, etc. Between 1949 - 1952 (3 Seasons) Matthews scored just a goal in 87 domestic games (League and Cup). He also scored no goal for England for 7 years in row between 1949 - 1955. Winger must help the team to do scores as the proportion they have potential to do and Matthew failed in this function. Therefore, you should give your idea which year Matthews would be right to win.