User blog comment:Kogath/Monster Hunter: World Discussion/@comment-25083735-20190713220054/@comment-24734669-20190713221751

TBH, we don't have enough info on how lower- and middle-tier monsters stack up with each other, so that should explain it.

Also, even if they do end up tying with each other, things change. Remember that Diablos was one of the few monsters, along with Brachydios, Gore Magala, Duramboros, Lagiacrus, Agnaktor, and Nibelsnarf, that was said to be able to drive off a Deviljho. Now, when Deviljho arrives, anything that isn't dumb old Bazelgeuse gets put at a severe disadvantage.