The Confederacy of Vulcan sounds incredibly stupid.
Why? Despite its historical resonance to Americans, "confederacy" is just a slightly different way of saying "federation." They're both from Latin foedus
, meaning a league, covenant, or treaty (related to the word for faith or trust). The only difference is that "confederacy" or "confederation" adds the Latin prefix for "together." So one is a group of states joined in a league, and the other is a group of states joined together
in a league.
Anyway, the books' "Confederacy of Vulcan" is no doubt a nod to the "Planetary Confederation of 40 Eridani" from Franz Joseph's Star Fleet Technical Manual
. They also refer to "The United Planets of Tellar" as a nod to the SFTM's "United Planets of 61 Cygni."