If it was prime Kovalev with a full training camp your statement would be true. Even Yarde lost recently.
Calling out the Krusher at 175 would have been more impressive 12 months prior and not after he had a life and death match so recently
I don’t know if I’d go as far to say they were fixed but Wilder didn’t give either much time in camp. I did think it was particularly strange that Kovalev didn’t sit on any of his shots given the fact he hits really hard.