I think this is the 4th thread on this subject but I believe that these NH trainers hit the market at just the right time. One of my (now) 15yo teenage help came out last Saturday and I found myself telling her she should buy young and started but NOT ruined when she buys her first horse--mom and dad aren't in the market to buy one for her.
I believe that people stopped spending adequate TIME with their horses in the 1990's and theses horses were changing hands without retraining out obedience issues. CA, and the others aren't trainers so much as they are RE-trainers. To see good initial training I watch Dennis Reis and Chris Cox.
(I'm wondering if Natisha is watching him or his horse, lol.) The horses that they turn out are the proof in the pudding. I remember a Cox program where he took a 3 yo to an eventing course in TX. His gelding was obedient in the Dressage arena and he taught him to jump a log on the ground before trying it with him aboard. ALL of the time the horse was calm, and flexed. He also had a program introducing neck reining to a 2yo and the result is what you WANT in any horse, accomplished in a short period of time with logical reasoned steps that you can duplicate.
Dennis Reis demostrates to ME in his programs that you can be the boss, in the same way that my horse, "Tyke" (1970-1998, RIP) established HIS authority (1994) with another's horse. Tyke was tied to our trailer, the other horse was tied about 12 feet away on another trailer. Tyke took ONE step forward, the other hesitated, took one step backwards--dominance established. Tyke was the bossiest herd leader I have ever met and I never saw another horse that didn't back down to him.
Reis maintains his ground and insists that the horse moves without smacking a whip aroud all of the time. His methods are easy for me to understand and duplicate.
I have used CA's techniques, but I cherry-pick. I don't think I've ever seen "Tyke" or "Corporal" or "Lawman" (Cup & Cakes) make another horse lunge 5 steps one way and 5 steps another way, back and forth, to establish herd leadership. I did see "Corporal" cow-kick "Prime Time" (TB) when turned our immediately after he saw Prime Time give
me some disrespect. In FACT whenever I had a problem horse in (my old) herd, the entire herd would beat that horse up for me.
Still, CA has sound methods. He
Lucked into the tie ring, but it makes perfect sense to use it early on yearlings. However, I kinda wonder about a few things.
CA tells stories about how he had problems with his horses growing up that I didn't experience until, again, buying horses in the late 90's.
"I thought that you were lucky if your horse loaded easily in the trailer.", for instance. "Corporal" loaded into my trialer as a 4yo (1986) with a piece of baling twine bc we weren't expecting to buy a horse that day and didn't have a lead rope with us. The ONLY horse that was a trailer problem for us was an old mare that was having sight and other problems. Everybody else did fine. We even (blush) loaded 5-6 horses several times into our 4-horse stock trailer. Our big barrelled, 13'2hh pony, "Toma", would load himself between 2 other horses in the back.
All I had in my arsenal was 3 years of hunt-seat lessons, but I re-trained horses with minimal problems, or retrained Western to English and all to gunfire and close-order drill. I've usual manuals and books and learned by doing. I kinda wonder why CA insists that he needs the advice of others to train his show horses. =/
To ME, you train a good foundation on your horse and the rest is just gravy.
I STILL watch his programs to see if there is anything I haven't thought about. I am learning from Julie Goodnight in her starting a colt series that's on right now.
Parelli's advice sounds workable and then they throw in advice like pumping your legs alternately to get impulsion.

I even tried it with my 5yo QH--didn't lighten him up. My spurs did, however, and he remembers. I had always learned to whisper with my calves and use a crop behind my leg if my horse turned off his "hearing." After awhile my lesson horses would see a rider flip their crop up and immediately responded with more energy before the crop was used. You know, they have this "peripheral vision" going on. =b
Sorry for the length. I suggest watching them, but check here to see if anything they say sounds fishy.