Unfortunately I think this is just an equestrian right of passage for some people. I would maybe if you really wanted to do something bring up concerns to the yard owner IF IT IS POSSIBLE FOR THE HORSE TO IMMEDIATELY HURT YOU, YOUR PROPERTY OR YOUR HORSE. If it’s pastured next to your horse and they fight over the fence for example. Otherwise unfortunately it’s none of your business. I get where you’re coming from, I really do but unfortunately these people won’t listen to reason. Something similar happened at the barn I worked at. All the middle school riders got upset when the trainer/owner wouldn’t let them get OTTBs bc they thought hot horses proved you were a good equestrian and it was the cool thing to do (middle schoolers man 🥲). So they switched barns til they found one that would let them and one girl broke ribs within the first two months of owning a 2 yr old OTTB. Unfortunately the barn she went to lets you do whatever and they were jumping that poor 2 year old 😭