I've always shot a shorter draw than most people think I should. I am primarily a Hunter and I find that a slightly shorter draw length allows me to stay behind the shot and be more consistent in all the weird positions you can get in while trying to pull off a hunting shot.
Shooting in the woods is not the same as towing a line at a Target
There are some people that have obvious form flaws that need corrected, but not everyone is going to shoot with the exact same form
The key is repeatability. Do the same thing the same way every time. The trick is some things are harder to repeat than others[8D]
Dan