Rich,
C.B. MacDonald has been quoted as saying his model for the Short was the 5th (now 4th) at Brancaster). I believe Jim Kennedy has the direct quote somewhere earlier in this thread. While the 8th at the Old Course is named Short, it has nothing to do with the short hole template.
The Long hole is a tough one, and by all accounts it was usually MRB's weakest template hole. In all fairness, though, the Long hole does have a lot more moving parts than, say, an Eden, or a Road. Moreover, not every template hole was constructed on every MRB course. How many Saharas are there other than NGLA? Even so, my understanding is that the "Long" hole at the Lido was pretty solid, replete with a fearsome Hell bunker. Of course, we'll never know for sure.
Remember, too, that all templates don't have to be exactly the same. It's likely true that most "Short" holes are not in the realm of 6 at NGLA (I can't register an opinion--I haven't seen NGLA). However, most follow that same basic idea of a short par three to a large green that was subdivided by bold, often horseshoe-shaped, contours. MacDonald and Raynor didn't build short par threes with small greens, whereas other Golden Age architects (Ross, Colt, Tillinghast) did. If there wasn't a template for the "Short," wouldn't MacDonald and Raynor have built several short par threes with small greens in proportion with the length of the hole? Clearly, somewhere along the line, someone in that group decided that a short par three with a large, subdivided green was the way to go.
As for Ross reading CBM's cryptic writings, I obviously have no idea. But Ross's use of central horseshoe contours on a few his short par threes seems too good to be coincidental. These contours have a similar appearance to those on the MRB Shorts, and they have the same strategic affect. Folks always get deeply offended when I suggest that Ross borrowed ideas from his Golden Age cohorts, but the short par three with horseshoe contouring was definitely something that came before him Moreover, those horseshoes don't just pop up out of nowhere in the middle of the landscape. Yet just as Yeamans Hall's Short is different from the one at NGLA, so to are Ross's Short holes different from MRB's. Oak Hill West's 4th is the most dramatic I've seen. Even so, all of the holes I've listed follow the same basic template with variations on a theme.