I think a great example of the heraldry norm =/= fraternal significance can be found in this 1930 article L.G. Balfour wrote regarding the Delta Chi CoA (found here:
http://www.deltachi.org/quarterly/su...all_03.pdf.pdf). Balfour talks a lot about heraldry, and its all actually great information, but his discussion of our CoA, while interesting, has almost nothing to do with the Ritual significance of the arms. Of course non-members couldn't compare, but it's a decent article regardless.
Also, I commented in another thread that the open meaning of our CoA (that is, the marriage of two families) was so comprehensive that I was surprised to learn there could be any more to it!