I’ll bring this up as we are approaching hunt season in just two weeks. I was out on a hunt trail ride recently. There were some people out with herd bound horses and were telling everyone they couldn’t be separated, etc. As we were going along we had to go around some down trees. The rider on the first of the herd bound pair went one way and the rider on the other another. The second horse got frantic and kicked out and caught the horse… Luckily the horse that got kicked was far enough behind that it took a weak kick. No damage.
To me, bringing horses out like that is dangerous to other riders and horses. If they can’t be separated in the field, then leave one of them home. IMHO