I believe that the best trainer is the kind that does not rule anything out (unless it is cruel) that could benefit their horse. I suppose if we were categorizing ourselves I would be in the natural horsemanship group, but that doesn't mean that if I was training a horse that I would not consider all methods of training.
There are some "natural horsemanship" trainers that I have met that make the mistake of putting "conventional training" on a level of cruelty to horses. Horse cruelty is whipping scared horses etc. Although I am not 100% sure how I feel about bits, riding in a snaffle bit is not animal cruelty. I believe that there is no such thing as a "bad horse that can't be trained". I believe that horses and humans have a mutual agreement and the lines can sometimes get blurred between "I am here to serve the horse" or the just as bad "I am the boss! I rule this horse!" attitudes.
To me, we provide horses with love, care, shelter, food, water and the all important leadership and with that the horse offers us whatever he/she can. Also I believe that some people are too tough and some people make the mistake of rolling over and letting the horse trample them. People have to be realistic too. Horses are big and weigh a lot more than us and we have to be careful not to get too lovey dovey. For instance, a while ago my horse was scared and spooking and jumping into me and I would go "Oh its okay Rosie, I'm here sweetie" That was a big mistake because she wasn't looking for me to stop whatever was scaring her, she was just bulling me over.
So basically haha I think it is a tough but, possible balance.
Ask not what your horse can do for you, but what you can do for your horse.