Here is a unicase analysis and experiment I made in reducing the number of upright/roman glyphs able to represent the three related scripts.
I had created a Unicase feature for Scotch Modern, in Latin, and thought that the same feature should be available for the other scripts, and made it so. This diagram followed that thought.
I concluded that Cyrillic is already pretty much common-case already, and that unicase does not sit well with Greek. Other than that, it was interesting to see how elegant the diagram that emerged could be, although I don’t think that’s very significant.