If you ride the horse away from buddy the first hint of reaching a threshold, when the horse is uncomfortable and wants to avoid continuing, then return to the horses area of comfort and train her to back, circle, disengage, go whoa, turn stop, back up etc in a calm clear non confrontational training mode then relax and ask the horse to leave again. Repeat as needed. Understand threshold. This does two things. Develops trust from the horse because you are reading the thresholds and giving her comfort but then respecting you as a leader because you are giving her a job if she wants to go back with buddies. Yes the horse will work more than you. There won't be a lot of contest of wills and the horse will get it. Some sooner than others. It's not about the head gear it's about the communication and relationship. My horse got to where she would actually slow down on the way back to the buddies and the buddies ( used to be screaming at the fence line type of thing) would be at the top of the pasture staying away and doing the "looking" thing. It works.