the way you could look at it is

mayweather - elite lb4lb boxer
canelo - elite boxer
haye - world class top 5 HW
Fury - very good HW, possibly top 10

someone said if fury hits haye he could KO him and thats very true but Haye has been in with the best of the best at HW and that didnt at any stage look likely

and no matter how good mayweathers recovery powers are canelo could KO him if he catches him just the same