Vance,
I gave up on the traditional look for this tree when I realized a few years back that it got away from me in the branch system. Ch. elms of which this a product of, take a lot of daily work to keep them from looking bushy and more tree like, more time than I have to devote to one species of tree since I have five ch. elms in my collection.. That being said I decided when I did the restyle, to just see where the tree wants to go and maybe help it along. I know the rules are for an odd number of trees, but these trees have been joined together since I bought them and back then I wasn't aware of any rules. A few years after the restyling I decided I would go with the tight foliage and more of the chinese penjing look and not worry about the rules. Had I decided to with the more Japanese style and have the branches more open and separated, I probably would have done the three tree look.
As for waiting for the tree to fall over, come on. The only way that tree will be more apt to stand on its own is if I prop it up with something or wire it to the tree next to it, both of which I'm not willing do because of my own personal viewing aesthetics. The internal root system is very good, but the main top roots which are all entangled together are what holds the trees together. They have been that way for probably twenty years,and after watering them for that long, that one decided to rot away. It's no big thing, the underlining roots will continue to hold them together I'm sure, only not as well as I would like.