Are you stupid?

Horse hearts are massive compared to human hearts. They would just die.

I think you’re forgetting the Nintendo DS family.

One of them was literally just named “New Nintendo 3DS”.

None of them really have a hierarchy at all. Dogs, cats and horses are usually just a breeding pair and their offspring. Actually foxes are the only animal you named that does live in a structured hierarchy.

Nope, none of that is true. None of those animals have Dominance hierarchies.