In real life, there are weight classes in combat sports.
In my world, there are sixteen species from the Homo genus:
- Anatomically modern humans (Homo sapiens);
- Marine humans/Merfolk (Homo maritimus);
- Winged humans/Angels (Homo angelus);
- Horned humans/Demons (Homo demonus);
- Magic humans/Wizards (Homo magicus);
- Arboreal humans/Elves (Homo macer);
- Ogres (Homo corpulentus);
- Giants (Homo gigas);
- Hematophagous humans/Vampires (Homo haematophagus);
- Furry humans/Therianthropes (Homo pilosus);
- Green humans/Goblins (Homo viridis);
- Tusked humans/Orcs.
These various human species have an EXTREMELY high phenotypical variation between them. Some examples include:
- Merfolk are as massive as belugas with females larger than males, they have a seal-like blubber, and bison-level strength, and, while they do have hands and feet, they are syndactyl (webbed digits) (sorry, I do not want a psychedelic-like species like merfolk from a famous Disney animated film).
- Giants are as massive as polar bears with females larger than males, and they also have a seal-like blubber, and they have moose-level strength.
- Ogres are on average as tall as the average real life NBA player with females larger than males, they also have a seal-like blubber making them weighting on average 140 kilograms, and they have gorilla-level strength.
- Gnomes are as small as domestic cats, and they have raccoon-level strength.
- Angels are as large as wandering albatrosses, they have bat-like wings, and beaver-level strength, and they can fly as well as African grey parrots.
- Demons have goat-like horns, weighting on average a metric ton, the queen is always the largest individual in a demon colony (they are eusocial like naked mole-rats), and workers weight on average only one kilogram.
- Vampires are as large as common chimpanzees, and they have chimpanzee-level strength.
- Therianthropes are as large as orangutans, and they have orangutan-level strength.
- Orcs are as large as American black bears, and they have wild boar-like tusks, and zebra-level strength.
- Wizards, naturally, can use magic, but without it, they have dog-level strength.
So, the question is: how could interspecies wrestling fights be fair if all the various human species are EXTREMELY different both in terms of size (volume, mass, and height), and in terms of physical strength?