I use Parelli. But I would be very
careful about who you call a "natural horseman." Pat in my opinion is a prime example of what a natural horseman SHOULD be. Troy Henry, Tom Dorrance, etc. are others, but IMO the majority of the other "natural horseman" these days are not natural horseman at all. NH has become a phrase that has been VERY over used and it's lost its TRUE meaning, which is why Parelli has taken out the Natural Horsemanship in it's name. They refer to it now as the Parelli Program. They don't want to be associated with the people who CLAIM to do NH but they really treat every horse the same, it's a cookie-cutter program and that simply does not work. Parelli does not do that.
I love the Parelli program. I believe in what they teach and I've seen it work time and time again. It's for every horse, but it may not be for every person.