Hello from another Suffolk resident! Don't believe i've ever heard of the group you linked to, may look into it out of curisoity
I think the problem i have with the whole NH movement is that a lot of it is common sense horsemanship wrapped up in marketing. Parelli being a classic example - is it true that to go through the levels you need to have all the branded gear?
I'm all for having a relationship with your horse that goes beyond riding (it does pain me to see hyper-competetive riders hauling their jumpers around for the sake of a rosette without so much as a kind word) but maintain that you don't need a carrot stick and knowledge of whether your horse is left or right brained in order to share a bond! I don't own a horse at the moment but my long-time friend is a great example - she owns 2 very different horses and has never so much as had a rope halter near them but shares a great bond with them
Sure, NH works for a lot of horses and owners (i guess that those horses who need lots of mental stimulation love the games!) but it's not something i would ever buy into beyond the basics.