Robert Whittaker is a great fighter and his strengths come from being strong, explosive Middleweight and he has decent amount of power in his hands tho not the most technical guy he has been out-manuvered by Izzy without exiting 1st gear..
Whittaker can stuff and shout down someone who is using pure brute force but he can't shout down someone who is extremely technical and skilled.
Khamzat is just way to technically good to get stuffed by Whittaker and despite Whittaker being strong Chimaev is stronger imo but it is the combo of the technical aspect that would be the huge gap.
Whittaker doesn't like to get also pressured and that is why Izzy KO'ed him and what Khamzat does is nothing but extreme pressure. Even in the striking department Khamzat has slight stylistic edge that most don't realize.
But I see it differently tho? I mean how it will unfold! I think there will be several scrambles and in one of these Khamzat strangles whittaker in the 1st round with 75% chance it being the likely outcome..
As good as Whittaker is but there is levels to this in my honest opinion and Khamzat is the way more technical and skilled fighter..