Josh, I think the trouble we are having is you are looking at individual kata i.e. three kata named sho, chiku and bai.
I like the idea of SCB=3in1=TriCirSqare but I can't limit it to just 3 individual kata. I don't see that.
Doug, I apparently haven't been clear, and for that I apologize. Getting a big bogged down in minutia, I guess.
I am not looking at three individual kata as the whole of "Sho-chiku-bai no kempo". Rather, I'm looking at the three Hikitsuchi kata so named because I think they provide a viable clue as to why Ueshiba used that name.
I'm looking at it this way. Ueshiba referred to "Sho-chiku-bai no kempo". Okay, what does that mean? Why "Sho-chiku-bai"? Well, it certainly isn't referring to the trees themselves. What examples do we have of him using it?
Professor Goldbury has provided some of those examples, but they don't exactly suggest why "sho-chiku-bai". OTOH, Meik Skoss and Ellis Amdur say that there are three kata in Hikitsuchi's ken called Sho, Chiku, and Bai, and that the first represents Irimi (triangle) , the second Tenkan (circle) , and the last Osae (square).
Now, as Professor Goldsbury has pointed out, how much of this is direct from Ueshiba, and how much is extrapolated by Hikitsuchi, we don't know. But forget the three kata themselves for a minute. Here we have a clear connection made between the words Sho-Chiku-Bai, and Ueshiba's favored symbols
. We further have connection between Sho-Chiku-Bai and Irimi, Tenkan, and Osae, basic principles of aikido engagement.
So, from my perspective (admittedly on the outside looking in at your kenpo), it doesn't matter how many or what kata one might have in one's swordwork. Being called Sho-Chiku-Bai would seem to suggest that it represents these fundamental principles of aikido:
and/or Irimi, Tenkan, Osae. (Noting of course that often in these kinds of situations something can have multiple, layered meanings.)
Of course, this isn't "the answer". It's merely a suggestion, a clue, a lead to follow. I suspect "the answer", like the meaning of
, can only come through one's personal understanding of one's personal aikido.
Consider everything else I've written on "Sho-Chiku-Bai" (produce, grades, etc) as providing idiomatic background, so one doesn't assume it just refers to mere trees.