First, welcome to the forum Kathy
. I will echo what everyone else has said, I would visit with the better instructor about sticking with the trustworthy horses for now. Maybe after you have gotten more experience and your confidence is better, you might be able to help put some miles on the non-bucking rescues. It may just be me, but I don't think I would consider putting anyone less than an expert on a horse that was a probable bucker. Not only does it risk serious injury to the person, but it doesn't do the horse any favors either.