At a given frequency, the radiation pattern's angular coverage is inversely proportional to the width of the source in that plane. The Maggie MG12 is a great example: Set up normally, the tweeter is narrow in the horizontal dimension and broad in the vertical, so its radiation pattern is just the opposite: Broad in the horizontal and narrow in the vertical.
I do not know the orientation of the tweeter element in the CC3. If it runs horizontally, then I'm afraid that 36" horizontal dimension means it would be beaming pretty badly across the treble region. However if the ribbon element runs vertically, then it will have nice, wide dispersion in the horizontal plane. That is my expectation, but I don't know it for a fact.