"the male is typically the dominant role"
Hyenas.
That is all.
Anglerfish...
In most birds of prey, the female tends to be larger, and at least for some species, both sexes have equal partnership with incubating, hunting, defending, and cleaning the nest (from what I've seen watching bald eagle cams).
And then there's animals that live solitary lives, where the male leaves after mating season is over. You mean to tell me that animals that live alone don't compete for resources? Seriously, what has this guy been watching? Animals where one male rules a harem?