What is the maximum number of units that can be added to the game? I have heard there is a limit. I didn't see anything in Duke John's Unit Guide on this, so...

BKB's Mod has 256 units according to the Gnome Editor and the Reconquista Mod has 325 units according to the Gnome Editor. I am not sure if the Reconquista Mod uses all of the units, or if this makes a difference. Does anyone actually know the maximum?