Go check all the defensive metrics and get back at me. Durant is top 5 among SF and top 30 overall. Klay doesn't even appear on the top 40 SG (he's behind James Har_en

).
I don't know where this perception of Klay Thompson being anything more than an average defender came but it just isn't truth. Durant on the other hand is very underrated on that end and when engaged he can become a lockdown perimeter defender as well as a terrific rim protector. Anyone that watches games with a couple of functional eyes can realize that Durant >>>>>>>> Thompson on D.