This assumption is false. There is quite a bit more complexity than you are aware of. Even if a rule were written out, substituting devices would not be just a simple thing to accomplish. The effort for a user would be just as tedious, in a different and more obscure way, more prone to error, harder to document, etc. So, it would require yet another online interface to make it easy to use.
Best analogy would be going from a high level language, to editing binary object code or assembly language code. It's all there, but not in a form easy to see and edit.
