Well, I'll put my flameproof suit on here as I'm sure this won't go over very well, but here goes. Yes, I have started horses that way, but not minis. Minis are little enough to hold by hand if they get scared. With the big horses I just couldn't handle them if they decided to go ape. So I'd ground drive them, then I'd ground drive them while someone else pulled the cart alongside, once they were quiet with that they would bump the shafts into them while I made them turn etc..... Now that they were comfortable with pulling I'd get the wheel loader (which had a plate across the front so there was nothing for them to get their legs stuck in) and I would tie an inner tube to each side of the bucket with a rope coming down and I would cross tie the horses to the bucket. Of course the bucket was high enough in the air that they could in no way hit their head on it. Once they were leading nice, then I would have four people come out to help me. One in the loader, one on the horses head, and two to put the cart on. As soon as he was hooked up the loader would take off leading him. I started more horses than I can count like that and all but one just walked off. Had the right ground work done and could have just hooked up the cart and went, but there was one that I was very glad I had hooked to the loader. He was fine until the first turn. You know how they have to sidestep in the shafts. Well, he didn't want to do that and just went crazy on me. I am certain that I been alone, or even with some ground crew he would have dragged us all into the fences and run until someone died. This way when he went crazy, trying to kick the cart, lunging, trying to run etc..... the head of the loader was raised until his front feet were almost off the ground. As soon as he stopped acting like an ***** he was put on the ground to try again. There was absolutely no way for him to hurt himself. It only took two times of this and he was quiet and did turn. I really like doing it like this (considering it is all set up where it is safe) as I can totally control the situation without getting the horse all worked up. Before we started this method we had one that had all the ground work done, but just lost it when we hooked her up. We had one person on each side of her with a lead line and one ground driving beside the cart. It was a huge wreck, when one of these big horses decide to lose it there isn't much three people can do to slow them down and keep them from hurting themselves. She came out of it without being hurt was was so mentally shaken because she totally wrecked the cart and we had to cut the harness to get it off her. I never tried to hook her up again and warned the people that bought her that they should NEVER try to hook her up. I have had much better success like this as I know they can't get away. I don't know if this guys setup is safe, but a similar thing worked great for me. JMHO and please don't kill me folks, it's just my way