I don't think Chimaev has much for Usman, Burns really tested him, and although Burns did test Usman somewhat, Usman sat behind the jab, and won the fight convincingly in the end. I have noticed though, that Burns does have a weakness to a good jab, so that did play a major role in that fight.
Usman has the skills to keep it standing I would think, and he beats Chimaev standing. Chimaev doesn't look like the unbeatable fighter he once was, obviously still very good, took on number two, and went to war. Although, he very nearly got knocked out a few times, I've mentioned before he basically face planted the floor, and was lucky to stay in the fight at that point.
For me I would love to see a war, even though Khamzat Chimaev would lose to Kamaru Usman, I still want to see that fight, I think Chimaev will surely have a chance even if that chance is slightly small at least he still has a chance in winning I think he will surely go deep to the fight against Kamaru Usman that is for sure and both fighters is expecting that to happen, for me I want an Chimaev to be the underdog but because of the Hype of Chimaev we could see a tie odds between this two but I could be wrong,
Btw, do you know that in upcoming Chimaev vs Nate Diaz fight, Jorge Masvidal will be a replacement in case there is something with Nate. I would love to see Chimaev fighting both of them. I see no real danger in both of them for Chimaev. Masvidal probably is going to be more convenient for Chimaev, as his ground skills are lower. Would be a good chance for UFC to get rid of Masvidal 3 losses in a row already. Nobody remember his flying knee knockout anymore (except youtube compilations). Has legal issues.