Larger units are not only more capable of controlling the battlefield through numerical advantage, they are also more likely to have surviving members. This aspect of the game makes units with a large unit size extremely valuable. However you can choose to replenish units up to their initial unit size by spending money to recruit troops which replenishing the unit. Losses of men in a battle are persistent. Unit size is listed in game in the upper left hand corner as 'men' followed by a number, this term while clear as used in the game can become ambiguous as the context changes.
Unit Size is a count of how many soldiers are in the unit.
