I am not sure where you got your data but male male mating seems to be rather well researched in animals.
Just grabbing one of the many quotes:
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One species in which exclusive homosexual orientation occurs is the domesticated sheep (Ovis aries).[8][9] "About 10% of rams (males), refuse to mate with ewes (females) but do readily mate with other rams."[9]
The part you’re missing is that all of those males that mate with males will mate with females as well.
The paper Wikipedia references about rams notes that the only mammals with exclusive homosexual behaviour are sheep and humans. Exclusive homosexual mating is exceptionally rare. There are about 6000 mammal species.
The Wikipedia sentence should read the only other mammal which exhibits exclusively homosexual mating behaviour is sheep.
Also domesticated animals have been under some pretty weird selection pressures so you have to be careful comparing their behaviour to a wild type animal like humans.
https://en.wikipedia.org/wiki/Homosexual_behavior_in_animals
I am not sure where you got your data but male male mating seems to be rather well researched in animals.
Just grabbing one of the many quotes:
----- One species in which exclusive homosexual orientation occurs is the domesticated sheep (Ovis aries).[8][9] "About 10% of rams (males), refuse to mate with ewes (females) but do readily mate with other rams."[9]