I would argue that the two are very different. There are enough pat vs Clinton threads here to prove that people view them as almost opposites. They both use pressure/release methods, both market the heck out of themselves, and have both made themselves look like fools at one time or another. Clinton is an effective teacher, and does well in groundwork. But there is no 'horsenality' or games with him. I'm not sure what Parelli is good at, as I've never followed his philosophies, but I would argue that developing a bond is important to him, whereas Clinton wants a horse that will do what it's told. I'm not a fan of either, but I'm just trying to point out some of their differences.
"But I can tell you this: When you get to square ten, all of square one will be in it." RayHunt