PCRW IS is first and foremost a structural definition of what a high level swing is, i.e. defines those bodily actions and movements that result in a high-level swing. "High-level" is defined as a swing that contains all the elements found in the best major-league baseball swings. The most efficient and effective swings as typified by those players who have a long history of achievement and accomplishment. Structural definition means that PCRW identifies the critical, essential characteristics/elements that must be in place resulting in a high-level swing.
PCRW is analogous to a swing "building code". The same concept as residential or commercial buildings must conform to. Building codes came into being because of a need to create universal system that guarantees safe and efficient building structures. Building codes define everything that is deemed critical to health and safety such as size, strength and composition of materials, workmanship practices, etc..
Building codes do not necessarily restrict the specifics of the process of putting the building together or restrict all building practices and esthetic design. But they do define/restrict much of how the final product must function (safety, longevity, efficiency, etc.).
And while many may claim that they are competent to design a building or structure or build it or what they build (the final product) building codes help insure the best possible product.
PCRW is It defines the structure and composition of a high-level swing. Creating a swing the "meets" PCRW or instructional information/methods that satisfy the requirements of PCRW is like the construction of a building, i.e. there are many architects, contractors-builders-trades persons who can create a structure conforming to building codes. The key element here is that in most if not all cases these companies/individuals are certified in some fashion. The hope being that the certification process will result in practices and final results that are consistent with building codes and requirements.