Echohawk
Shirokinukatsukami fan
Yes, I think the A series was released out of sequence.Going through the release dates, I noticed that the A series appears to be out of order. Were A3 and A4 really released prior to A2 or is there a mix-up there?
The Acaeum notes that "[A2] was actually published a short while after module A3, due to each module in the series being treated as a separate project at TSR," but doesn't mention A4.
The US Copyright office lists the publication dates for A1-A3 as:
A1: 1980-10-14
A2: 1981-07-07
A3: 1981-05-04
It doesn't seem to have a record for A4, but ISBNdb.com does (here), and that says April 1981. That should give us this order:
A1: October 1980
A4: April 1981
A3: May 1981
A2: July 1981
For some reason I have A4 listed also with a May date. That probably means that when researching these I found another source which I trusted more than ISBNdb.com indicating May rather than April, but I can't support that right now

(Warning: One of the OAs was also released out of sequence.)