How Horses Respond To New Riders – Video

Stacy Westfall has logged 143 Hours of total training time into Jac, the horse in the video.  She decides to let another rider on him for the first time and they documented the experience in this video.  At 7:40 Stacy makes a reference to seeing negative consequences to switching trainers frequently. This isn’t to be confused with switching riders; one person trail riding one day and a different person trail riding the next day. It refers to very active teaching and training. This ‘transition’ is also less exaggerated as the horse becomes more seasoned; older or more experienced horses handle the transitions between trainers better than young horses.   I completely agree with this.  What do you think?