I'll say it again, Khabib's dominance is largely due to favorable stylistic matchups. The LW division is incredibly thin when it comes to strong MMA wrestlers, guys that can stuff Khabib's takedowns and force him to stand with them.
Tibau was the closest thing to a strong MMA wrestler Khabib faced and he looked very very average the moment he couldn't take someone down. That's one reason why I don't have him in the top P4P list, he's too one dimensional, if he can't get you down he's suddenly very average, he doesn't have a plan B.
For example, GSP has the ability to adapt, if he can't outwrestle the guy (e.g Koscheck rematch) then he can stand with them because his striking is also elite level. Khabib doesn't have this option, and he's so lucky the LW division has 0 strong MMA wrestlers so he can get away with the same gameplan.
Imagine if he was a natural WW, guys like prime GSP, Hendricks, Koscheck, Usman, etc would all give him serious serious problems because they are high level wrestlers with incredible TDD.