The power rankings have never been based off of stats but opinion and observation; Wil beats everyone -> Will is the best -> Corey beats everyone but Wil 65% of the time -> Corey is the second best -> only person(s) that can consistently kill godzilla is Wil, Corey and Dusk -> Dusk is third and Godzilla is fourth.
It has nothing to do with stats because everyone in that over-all list is absolutely putrid and sat there for months and did nothing but spar when the tracking system for kills/deaths/overall stats in spars was released while the rest of us kept PKing.