Despite the FoW option (visibility conditional, info vague), you can select an ennemy unit and look at the interface (army hierarchy) in F3 or F4 to see all the ennemy organization, the number of corps and the number of unit in each of them, the state (color) of these corps and how many units are prisoners, diminished, etc....
What do you think about masking these informations in a way to have FoW in all part of the game?