At WW, Armstrong has a shot of being rated over him, but SRR still remains my number one guy at the weight. At MW, a case could be made for Monzon, Hagler, or Greb being rated higher, depending on the criteria that's used.
I can definitely understand a case for Hagler or Monzon but Greb, I've never understood how any type of case can be made for him in any discussion. There's only circumstantial evidence. For all the older guys that is
I have Greb at number 4. I think a lot of people judge some of Greb's Lt.Heavy fights as Middleweight fights...
Greb probably is #4 but I don't understand him being rated higher. Somebody would get laughed at for ranking John L. Sullivan, say, 7th all time at HW but a lot of those same negatives against John L. could be used against Greb in a fair world.