In the equestrian world, when a rider holds the reins and uses them to steer, stop, collect, and control the horse, we look at the "softness" or "hardness" of her hands.
Riders who jerk and yank their horses to get them to stop and turn are considered to have "hard hands." Riders who communicate very subtly with their horses mouths (usually you can not even see their hands doing anything, but their horses feel it and respond) are considered to have "soft hands."
I have been playing with this idea of soft hands and how it can be used in our leash work. Can a dog develop the same sensitivity to leash pressure as a horse, even though for the dog the pressure is against the neck and a horse has pressure in its mouth? If the goal of leash-training a dog is to have a dog who never pulls on the leash or creates pressure at all, then should we even worry about this question and whether your hands are soft or not?
My answers to these questions are Yes, and Yes. If you have experimented with the Silky Leash method, where you reward the dog for responding to ever-smaller pressures on the leash, you will see just how sensitive and responsive they can be. It has been my experience that a dog who understands this leash pressure game can respond to pressure as small as a minute twitch of the pinky finger. Of course, the more you work with your dog on this kind of thing, the "softer" and more responsive he will get.
In answer to the second question, about whether this is a moot point or not if they goal of leash training should be to have a dog who never pulls on the leash and is fluent on verbal commands, so why worry about it, I'd say the answer is also yes: it is still important to be cognizant of your hands and to get the dog to understand and respond to subtle leash pressure if needed.
There will likely be a time when either you or the dog become distracted, and one of you hits the end of the leash. Although I like to train dogs to walk so nicely on leash that there is *never* any leash pressure or tension, if for whatever reason there is pulling (either you getting distracted and pulling the dog, or the dog getting distracted and pulling you) I like for the dog to immediately realize what's going on, and go back easily into position.