If you've ever spent any time studying and watching wild horses, especially if you have gone as far as training, you will learn that you have to speak their language before they will learn yours. Round penning is not to instill fear if done correctly. It gives you a safe place to work with the horse and to build trust with each other and to learn to communicate. It provides the opportunity to assign a word to a behavior, which has immense value when starting under saddle or even just working on ground manners. We also use it to assess the horse's condition and gait. It gives us an opportunity for us to identify problems before we get on a horse. If we can identify a lanemess at grade 1 and treat it properly there, then we may have averted a much bigger problem.
My big question is, if you do not round pen, how do you safely start your horses?
Horse Tenders are a really good example of a small business that works with and places mustangs. They do an excellent job... all bitless. http://www.horsetenders.com/