I agree with most of what your saying, but I think you may be placing too much stock on the concepts. As I mentioned earlier, the concepts are meant to elevate something that one already possess. They are not meant to be a pool of knowledge from which a stand alone method is developed, not that this couldn't be, IMO it just wasn't the intention. Using Fung Gar as an example, it is not a stand alone system. It is a system of concepts and philosophy, that once learned, is used to elevated one's understanding of their current art, such as Hung Gar. If Fung Gar was to be used and taught in the same manner as Wing Chun, it would fall down the rabbit hole too, because it was designed as a refining tool not a general purpose tool.