I have four goats, a 2-year old, B-sized mini filly and a 33" mini mule. My goats are mixed breeds, and on the larger side. One, Spike, is a wether, the others are does. All but Daisy have horns. Spike had risen to the top of the pecking order before the mule came, about a year and a half ago.
When I moved Betsy (the mule) in with them, the goats at first were petrified. Betsy delighted in chasing them, which didn't help. I had to fish Moon out of the duckpond twice, and goats hate water, as a rule!
Syd (the mini) was only about 8 months old when she came, and while she is sassy, she hasn't quite got the bullheaded self-confidence that Betsy has. She started off herding the goats around, but Spike pretty quickly learned that he could back her off with a show of force. His horns are impressive, I can't say I would want her arguing with him! He keeps trying to bluff Betsy, but she doesn't care, she just wades right in and bites him. So the order of dominance remains Betsy, Spike, Sydney, and then the three goat does. I put the mini and the mule in their stalls when I feed them, the goats may squabble over their food dishes, but at least they each get the right amount. Hay is cause for more bickering, of course, but I put out plenty so everyone gets their share.