I think both methods have their good points, but with beginners, I tend to lean towards getting a starting point with the wingspan method. Form is usually very poor with beginners. The bow shoulder is forced towards the target. Their release arm is not in correct alignment. They tend to lean back. They also don't know what comfortable is. With every body part out of position, they have no reference to how it should feel. I think it can be good to force their body into a particular position. I like PA's method. Get close and them let them shoot a very bows with slightly different drawlengths. That said, I think both work well with the right person helping them to choose.