Now, now. You might want to learn a tad more about something before dissing it out of hand. I don’t know a lot, but here goes:
That “some guy” is CA or West Coast trainer Eitan Beth-Halachmy. He has written a book that explains his system. That’s more than most of us have done, right?
You can also do Cowboy Dressage in-hand. There are more letters (and even cavalletti-like arrangements of poles in places in the ring) so that you can do/train/demonstrate more stuff.
I went to a clinic and little show with a “fix a test” component to learn about Cowboy Dressage; I had already been to a “Train the Trainers” event for Western Dressage. They are different, though very, very early on I believe some folks were trying to combine them. At least that was true in Oregon where I lived and they wanted to have one umbrella organization for the whole state.
BTW, it may be that WD is getting better now, but there were some things wrong with it that I consider significant. Can you still ride two-handed in a leverage bit? That was a bit of compromise made in the beginning to keep some of the founding people and their discipline happy.
IIR, “Soft feel” was a great big watchword of the Cowboy Dressage. I appreciated that idea being baked into the discipline’s patterns, purposes and judging standards because Competition Dressage (at least) has allowed a certain amount of tension and, frankly, horse worry to be allowed in. For horses, especially, that’s doesn’t seem like a fair training standard; and for amateur riders, it seems a recipe for creating fear and “choked up” horses.