From Ian and Jeff's responses (thanks for your real-world perspective), it does seem as if attribution matters quite a bit -- at least to the person creating the course. If you're in business and (as KBM and Tom D., too, pointed out in a former thread on crowd-sourcing GCA) you depend on your name to garner business and feed your family and keep your creative spirit alive, then attribution matters. I can't see how it could be otherwise.
From the perspective of someone who enjoys sussing out who did what work on a course, esp. when that person is responsible for creating something that overwhelms me on an emotional and/or intellectual level, attribution matters.
Similarly, if I like a song, I want to know who wrote it, who played on it, who produced or engineered it. Ditto other artforms.
Steve, your North Shore work is a good example of studying each course on a case by case basis. If attribution did not matter, John Newport wouldn't have that story.
Pat, I do think it's worth the effort to tease out those changes to the architecture. Steve's adventure (or George Bahto's lifetime CBM/Raynor/Banks passion, Phil Young's Tillie research, Neil Crafter's recent Mackenzie stuff, Joe and Mike's Cobb Creek work, etc. ad infinitum majority of threads on the site) demonstrates that it is possible.
But it still does not dismiss the need to determine who did what work on a course and how one establishes some sort of heuristic outside of common sense, which is not always "common" from person to person.
Tom M, certainly one does not systematically design and build a course according to prescribed "rules" of golf architecture, but design attribution has little to do with how the creative process unfolds, and more to do, broadly, with the end results of and subsequent changes to that process.
From the tenor of other attribution threads, one would imagine that there aren't many mysteries left out there, which is obviously, as Sean notes, not the case.
Thanks for providing a methodological starting point, Peter and Sean. For me, too, the soul of the course is established with the routing and with the sequencing of individual hole designs within the original routing; owners may or may not make modifications to individual holes over time, alter the original routing, redo holes in part or whole, etc. All of these activities change the course in some manner and affect one's GOLF EXPERIENCE, no?