Kyle Walker don't work as a metric against other players. He is basically Usain Bolt who can play a bit. I remember a very long time ago fifteen years listening to a Bristish Olympic coach they asked who was the fittest person he had ever worked with. He said unequivocally it's not a sprinter it's Kyle Walker the soccer player. He is the strongest fittest person we have ever tested. His recovery and stamina are unmatched in any sport. As you can imagine it stuck with me as it was so unexpected.
Walker is more than Usain Bolt who can play a bit.
The guy is a freak in terms of his pace and power but is also a more than decent footballer.
Fair I think to say that if he had possessed let's say Neville's ability to cross a ball, that he would nearly definitely be rated as the very best right back of the PL era thus far.