Just to offer a different perspective. I know that today there is an established sequence that most people use because that is how most were taught of snt then ck then dummy then bj and that you learn form first then drills then application. But I wonder if this is really how things were done always. I have heard that teaching was usually much more piecemeal and unstructured where you learned movements or techniques first for example stepping with punching and only later learned forms. This is how I was taught. So my perspective is not that the snt is the first form since we learn that form first first but because that form is concerned with dominating the centerline which is plan a or what we try to do first. The ck is the second form not because of the learning sequence but because it is concerned with changing and breaking the centerline which is plan b or what we do if we cannot dominate it. The bj is third because that is plan c of what we do when we cannot dominate or change or break the centerline.