I've thought about this too. It's kind of weird to look back on because I mentioned that there might be 13 other figures, but dismiss the idea. Well, 11 more have shown up. 
Yes, I immediately thought of that thread too. (In fact, I linked to it in the thread where Arforbes shared his tree discovery.)
What needs to be done now, which I plan on doing asap, is to analize parts 15 and 21 (the parts that the original SRs belong to) using MDB and the tree theory.
I think it is highly likely that the SR within those parts are all part of the same tree. Still, and analysis is necessary.
I think Alex’s discovery shows us how the Kin were made, but I don’t know if we can definitely say that Bandai used the same process for MUSCLE – simply because there aren’t all of the same figures.
I agree that caution is needed, but once you look at the data, it is obvious that MUSCLE color is directly linked to the trees within each part.
For example, lets say part X consists of 9 figures.
#
001
002
003
004
005
006
007
008
009
When we analize the figures by which colors they have been found in, a pattern quickly emerges, like so:
# Green Blue
001 Yes No
002 Yes No
003 Yes No
004 Yes No
005 Yes No
006 No No
007 No No
008 No No
009 No No
Once you see the pattern, you can seperate the figures into their seperate trees in which they were molded.
Tree One
# Green Blue
001 Yes No
002 Yes No
003 Yes No
004 Yes No
005 Yes No
Tree Two
# Green Blue
006 No No
007 No No
008 No No
009 No No
A pattern emerges, dividing the part into two seperate trees. Once we determine which figures belong to which trees, we can predict that the figures will all be found in the same exact colors.
Thus, figures 001-005 will all have the same pattern of the remaining six colors, and likewise with 006-009.
For example, if figure 003 is found in Magenta, it means 001, 002, 004, and 005 will also be found in Magenta.
Analysis of Kinnikuman parts using MDB confirms this!
Edited by Soupie, 22 March 2006 - 08:13 AM.