Hi Ben,
Great observations and questions about this complicated set of coins. I'll try to make this short:
-- The order of the varieties goes all the way back to what I believe was the first attempt to order and classify all of the anonymous
types. They are recorded in Alfred Bellinger's 1928 paper "The Anonymous
Byzantine Bronze Coinage."
His primary source material was the large numbers of anonymous folles found in the
Corinth excavations. For the Class A table, he also drew from known
museum collections, such as the
British Museum Collection and the
American Numismatic Society Collection. As the first creator, he chose to order it starting with the nimbus ornaments, then by the book ornament, then the
reverse. It was by convenience only.
-- Several researchers have attempted to make sense of these ornaments, and many theories have been proposed (
mint marks, dates/years, etc). A
good summary of the various theories and
his opinions about them can be found in the DO
Catalogue (Philip
Grierson) - Volume 3,
part 2, starting with page 644.
-- Regarding the
obverse ornaments on Varieties 41-42, I'm not aware of any particular meaning of that ornament relative to the others as of yet. In general, Varieties 41-42 are
part of the group of varieties that are smaller in size (along with
Var 24, 32, 39, 40, 43, 45, 47 and a few others). Based on
hoard evidence, these seem to have been made late in Basil II's reign (the last phase of Class A).
I
hope this helps.
Kevin