Inconsistent "out of" rankings

https://www.warcraftlogs.com/reports/qwbyhr8MANZaFTQg#fight=10&view=rankings&playermetric=dps

In this report, two Beast Mastery Hunters are present. One is ranked Out Of 1578, the other Out Of 1475. Also, either number feels much smaller than I expect, but that may be unrelated and Not A Bug.