To some degree, those things happen between horses, if a rider isn't watching it develop, or doesn't know to watch for it, you can find yourself in the middle of a dispute over pecking order. Sometimes the riders unknowingly bring it on by doing things that send the wrong message to the other horse. Your place in line might violate some equine pecking order idea they have in their head.
My advice to all people all the time is leave a lot of distance between you and other horses, even if the horses know each other well. Don't let your horse tailgate, and warn other riders that are tailgating you. You'll learn to recognize, from ears and tail swishing, when another horse is too close for your horse's comfort. If you go to pass, hold the outside rein to keep them from being able to interact with the other horse, and if you stop.... don't let them sniff noses. Horses will sniff noses then strike if they feel threatened... and the restriction they feel with a rider on and reins tight can be the only thing that makes them feel threatened.
It seems all the horses are being ridden in an egg-butt snaffle, which is about the mildest bit there is. When they want to 'go' do you feel like you have enough 'whoah' or to you have to pull pretty hard?
I do feel that I have some degree of control over the horse, but let's face it - I am an inexperienced rider and these horses have been on this trail so many times that what I say or do means almost nothing to them.
I got tough when I needed to by pulling Foyt's head towards my knee when he wasn't paying attention to what I was saying and trying to do his own thing.
It irritated him, but he respected the fact that I was trying to lead - albeit not perfectly.
BlackJack is an intimidating horse any way you slice it. He wanted to go after Foyt and he eventually did. Once that happened, there was little I could do besides hold on and try to calm Foyt down enough to slow him down.
I just said "Easy, easy, he's gone." over and over while pulling back on the reins with constant pressure. That didn't work, so I was forced to pull his head toward my right knee and hope he'd get the hint.
All this while I clung to his back like a tick! LOL!!
He did, to my relief. He could have just as easily thrown his head forward and taken me with them.
Oh! And no water crossings on the trail besides over bridges and next to canals.
We stay as far from the canal banks as we can though because of gators and the possibilty of a horse spooking and diving into the water.
It's 11 feet deep in some places. No good for horse or rider.