those 3 old sets sold more than 4000 boxes each, which is about 3 times more, than usual production run of a set these days. That gives us some hope for commercial prospects of ACW sets. Having said that, one should bear in mind, that there were no viable plastic alternatives to these sets back then, as all other sets of different manufacturers didn't cover this subject, whereas there is no lack of rank and file soldiers for this conflict. We shall see how things will develop in time and adjust our plans accordingly.
That's awesome news regarding your original 3 ACW sets. Your Team made the right decision offering something that was unique and you were rewarded for it.
I think you are lucky that the ACW and the Napoleonic Wars were very similar tactically speaking. The news of your decision to offer "Advancing Forward" sets for both themes as a follow-up encore to your existing sets is being well received already.
So, although jumping ahead, I would like to agree with your other fine customers herein who are recommending maybe next, a "Firing Line" set with firing and reloading poses to begin with. Both the Marching/Advancing and Firing Line sets would hopefully prove to be useful and popular with both War Gamers and Collectors alike.
I don't think you can lose by sticking to the basics. I would though, hope to see your sculptor continue what we are seeing so far, namely Confederates with blanket rolls, trousers tucked into their socks, both kepis and some Stetsons, the shorter shell jackets, and many wearing holsters, and looking smart and sharp. It would be easy enough to convert any down to the ragged look by the customer. And then Union Troops like Union Troops with longer frock coats and ...
As a concluding note, many of us on the forums have long stated that the existing ACW sets are long overdue for newer sets made to today's higher standards, exactly as your Team has shown us with your 2 new sculpts.