The default for infantry is 1 sprite represents 6 actual soldiers. On the options page you can adjust this from 1:1 up to 1:19. There is a limit of 200 sprites per battalion independent of the sprite ratio. Unit frontages will also not adjust correctly with the sprite ratio setting. This is included mostly for people who want to play very large engagements.
Design Lead: Scourge of War
"My God, if we've not got a cool brain and a big one too, to manage this affair, the nation is ruined forever." Unknown private, 14th Vermont Infantry, 2 July 1863