Hield is definitely not half the defender Klay used to be, but the trouble is Klay isn't the defender he used to be neither. The bigger difference comes from offense, Klay used to shoot threes like crazy, he would go nuclear, and he would shoot a ton, and now we are seeing him not have that type of crazy shooting anymore, the result looks different.

We should probably consider this as an upgrade for Warriors but barely. The biggest benefit they got is Hield is younger, meaning they will get this level of output from Hield for many years, whereas Klay got older and came back from injury, so he is not great anymore and getting older and worse. The best approach here is try to adjust Hield into Warriors system as quickly as possible.