Judging from the experience of Ancients, most VASSAL Epic play is done by 2 players. I'd see how EPIC Napoleonics goes before putting major effort into a new multiplayer module.
What might be a simple solution is to add a marginless board to to the existing module, which would allow boards to be butted together seamlessly, similar to The Great War.
I like EPIC games, but they work better and are more fun FtF