My horse is a LBE, passively dominant light draft type guy. His method of becoming a leader is ignoring any pressure at all. However, he was started with the Parelli method and since then he has been trained with natural horsemanship methods exclusively (ok, I know they are often similar with many traditional methods, too. ;) ), and this type of training has been only beneficial to him - he's now active, alert, interested in people, and, though passive dominance is still his game, I do the 7 games with him on a regular basis during groundwork and I really, honestly can say that he understands them and responds to them well. If to some only more active horses respond to Parelli - then my guess is something has been misunderstood in the whole pressure thing. It cannot be used as a system, it has to applied to each horse by his character individually.
I have come a long way, to surrender my shadow to the shadow of my horse.