Dominance in Horse Herds
It is not accurate to say male horses are inherently more dominant than females. Both sexes establish social hierarchies, and dominance is influenced by age, size, temperament, and experience rather than sex alone.
Stallions often have a prominent role due to reproduction and herd protection, but mares can also be highly dominant. Individual personality plays a major part, so there are dominant mares and submissive stallions.