OK c2u - why dont we start a new thread if you want to pursue this and I can talk you through each stage of scenario creation. Dont worry about unit icons - it may come as a huge shock but I already made a set of Napoleonics years ago for PeG which I can put in the OG dat file
One thing you should appreciate - Panzer General 2 was played as a 'campaign' which was a series of connected battles (scenarios). Your result in each battle effected the next, and your core units were persistent and moved from battle to battle gaining experience and abilities, almost like an rpg I guess. You could make a single scenario representing the whole Napoleonic war but it would be more fun as a series of battles (which has already been done for PeG btw). The 31 nations limit applies to an individual rule set (e-file) and could be used to the fullest extent in a campaign. However for a single scenario / battle you are restricted to two sides, one playable and the other AI. Each side may have units from 5 different nations.