To me, par 3s are the best place to get a bit penal with bunkers simply because so many 3s are too short to offer much strategy...the goal is to hit the green in the air in normal conditions. I can accept there is some strategy in aiming away from trouble, but real strategy in a par 3 can usually only be achieved by length....par 3s over 215ish or so.
The string of pearls, or for the poor man, half string, is a very common theme in 3s. There is a bit of artistry in disguising the concept with bunker shapes, off-set placement and fewer bunkers (what woman hasn't lost a pearl or tow in her string?), but the main concept remians still the same...hit the green in the air.
That said, I do suspect the concept was taken from somewhere and slowly or quickly spread, just like all templates. Its just that this concept is dead easy to recognize...most golfers don't recognize the MacD Templates or even think to look for them or even know they exist.
Ciao