I have not studied these cards in any detail but would expect that the cards were issued and re-issued in later years resulting in format changes, much like a Dan Brouthers N172 of the same pose being issued in 1887, 1888, 1889, and 1890 with similar but unique card layout/design each year. I suspect Dixie was introduced just prior to ATC merger but if it is found to be 1887 or earlier introduction than I'd date the first issue to about that time.
FWIW, an 1888 Virginia Brights and 1892 Dixie pack. Anyone aware of another Dixie pack in the hobby?