It is tempting to say that Khamzat trained for three rounds, would pace himself differently, etc...but what does that actually look like in a 5rd fight with someone like Usman (who we know can go that distance)?
Does that mean less grappling and therefore more time standing...because Usman was clearly getting the better of the standup.
Does it just mean still focusing on grappling, but being less aggressive with it in order to conserve energy...ok, but does that give Usman a better chance to counter it or to get up when taken down?
It's fine to say someone would pace differently in a longer fight, but there are consequences to being less aggressive, conserving energy, etc. if your opponent is thought to have a better gas tank and may not need to do the same.