Why are you adding in win bonus and sponsors? That has nothing to do with whether you are headlining or not and distorts the final number. Performance bonus? Of course that's going to make things look weird if an early fight gets those!
If you look at how many UFC fights each fighter has, and just look at BASE PAY, then it makes a lot more sense:
Jim Miller (37 fights) $ 111 K
Mike Perry (15 fights) $ 95 K
Kevin Holland (12) $ 70 K
Marvin Vettori (10) $ 49 K
Arnold Allen (8) $ 52 K
Mackenzie Dern (7) $ 54 K
Makes sense almost top to bottom, though Vettori should be in the 60-65 range. Maybe he signed a longer contract before his current win streak.