Good point. My horses are used to dogs and will actually chase a dog if allowed to but a lot of horses will get nervous.
I have been riding out on the roads before and had loose dogs come up on the road to bark at the horses and had to call the owners to come grab them before my horse turned them into a pancake.
As long as the dog stays out from UNDER the horse and doesn't bite, I can control the horses and keep them from hurting the dog, but that dog decides to nip at a leg and all bets are off. I'm not even going to TRY to stop the horse. A friend of mine even watched my herd chase coyotes out of the field where they had tried to cut through.
Wow your horses sound amazing and very intimidating, at least to canines! Haha I would love horses like that. There was this one at the barn I used to ride at that was sooo spooky and/or kind of hot so he was just hyped up a lot and spooked at stupid stuff lol