Chad probably has a quicker shot and better traditional wrestling in general, but Khabib has crazy core strength and ability to get takedowns from more ways. As far as comparing them for a Conor match up specifically, it's kind of pointless, because both of them would take (Chad did) Conor down fairly easily (~30-50% success) and control Conor from top position. Chad didn't get to train for Conor, so even being conservative I think Chad with cardio would do what he did in Rd. 1 and parts of Rd. 2 to Conor for at least 4 rounds. Khabib would likely be more aggressive, so he might expend a lot more energy, he'd probably have a much tougher time getting Conor down early in the fight. But it's not like Conor has great cardio or anything, so either of them would out work Conor most likely as far as grappling goes.