Thre is two Modules for C&C Napoleonics currently in use
vassalengine.org/library/projects/Commands__Colors_Napoleonics
CCNapoleonics4_1_16.vmod
which is the older, mostly manual with some automation of card drawing, leader checks etc. Most of you will find this familiar, and similar to other C&C modules.
CCNapoleonics5_1_0.vmod
is the latest, and is highly automated and conducts many activities like combat dice calculation and checking. It is a considerable step up in development, and many functions are unfamiliar to me.
You can use either, but obviously when playing a match, you much both use the same module, they are not cross compatible.
You should agree which version you are using when setting up matches, and in case of disagreement,
CCNapoleonics4_1_16.vmod
is the default for this tournament.
I have both modules loaded in VASSAL, and I encourage people to give v5.1.0 a try, but prior to playing a tournament match.