So let's talk realism.
First Artillery. Napoleon himself said this was the most important arm of any army and was by far the biggest killer on the battlefield. In this game you can fire forever and never cause any real damage unless it's close range cannister fire which is deadly. However, howitzers don't have cannister which is absurd because they used it all the time during the era. I've seen my lines get hit by shots and all the knocked over 'little figures' simply get back up. I fired my howitzers for 30 minutes into the center of a fort packed with cavalry, guns and men (foolish AI move) and after watching the shells burst all over the concentrations, above and in - I tallied 12 casualties. Absolutely absurd.
Artillery fire doesn't seem affected by woods, buildings yes, but not woods. Often artillery deploys in woods and fire without hinder. Absurd. You need a clear line of sight to be effective.
Cavalry. Totally wrong. Biggest error: All the cavalry in the game is hard wired to melee.
Let's talk just French (all the forces had similar units):
Cuirassiers were the heavy cavalry fitted with heavy armor and big horses. They carried pistols, sabers and carbines. They were slow and always fought and maneuvered in Column usually by squadrons. They would destroy light cavalry if they could catch them and often deployed to reaction charge or form grand charges with other squadrons. They were most often held in reserve for the final blow because if they charged too soon or without support, they would find themselves exhausted and in the middle of the enemy when they were easily dispatched. Most heavy cavalry was this type and most often used in charges and melee.
Carabiniers were Heavy cavalry with really large horses and men but not a lot of armor. They carried sabers, pistols, muskets until 1812 then carbines. Not very many (only two French regiments in total) because of cost and requirements to be seasoned and reliable soldiers. They served like Cuirassiers but were mauled by their armored counterparts.
Dragoons were medium cavalry in a sense and served as mounted but primarily designed as fast moving infantry to reach a point, dismount and hold until the real infantry arrived. In fact, the French had a hard time keeping the dragoons mounted as they were not really horsemen (clumsy fools as the Brits put it) and horses were sometimes in short supply. They carried sabers but didn't really know how to use them very well. Their main weapon was the long dragoon musket for fighting as infantry and later some were equipped with carbines (light dragoons). Used almost exclusively as mounted infantry - almost never as cavalry. Maneuvered in column. They charged in the early years but were not really good at it. Napoleon actually converted and retrained about a third of his dragoons to lancers to counter the Russian cossacks because they just weren't that good as regular cavalry.
Lancers were light cavalry armed with sabers, pistols and lances. The later being an excellent weapon for dispatching other cavalry and infantry. Maneuvered in column but always charged in a line formation often spreading out as the charge proceeded. Powerful charge but easily countered when they came to a standstill. Get in and get out. All melee type light and fast cavalry.
Chasseurs were the largest part of the light cavalry forces. They carried sabers, pistols and carbines and could and did dismount at times for fire combat. They were primarily a melee force used for counter charging, flank protection and specifically for pursuit cutting down a fleeing enemy. Often charged in line for envelopment and effect.
Hussars were light cavalry equipped with sabers, pistols and carbines but they were primarily a skirmish force designed to fire from horseback with their carbines to harass, slow and generally annoy the deployment of enemy forces. They also provided rear guard actions. They are primarily a fire unit though they did harass with their sabers as well. They deployed in skirmish formation and almost always avoided melee except at the end of a battle to chase down routing forces.
But in this game cavalry is not differentiated AT ALL. Despite being armed and designed as harassing skirmishers or as fire troops, ALL cavalry is hard wired to melee; ALL cavalry forms in one formation; dragoons are very rare; ALL cavalry seems to tire at the same rate; cavalry doesn't seem to be hampered by woods or towns except some slowing. This is so unrealistic. Cavalry wouldn't be caught dead in woods (or they soon would be) unless it was in general order and skirmishing. Hussars do well in woods and towns in general order but heavy cavalry would be useless. That none of the cavalry units can fire weapons is absurd. That charging through woods/towns would succeed is absurd. The cavalry units in this game are not designed historically or realistically. They have the names but not the function. They are simply differentiated by morale and melee value. And the formation is critical and not represented at all. They all maneuvered in column but fought in column, skirmish or line depending on their role.
Infantry is not differentiated any better than cavalry. They maneuvered in column and deployed in line for fire combat. They rarely moved much in line formation because uneven ground, obstacles, etc. would cause the unit to be constantly stopping to dress the ranks. So they moved in columns they would wheel into a line formation quickly or a square for that matter. And by the way, a square can move too. Not easily but it can move. Infantry also fought in general order in woods and towns not in line or column like this game. And where are the skirmishers? ALL Legere infantry has skirmish companies they could deploy that's why they were Legere and not line infantry. Where are the grenades by grenadiers? Where is the fast moving light infantry? Some are named like that but seem to move the same speed as any other infantry. Light infantry's biggest threat was cavalry which is why they excelled at general order/skirmishing in woods/towns where cavalry (shouldn't) be able to charge them. There is no column or line formation in this game just a blob you can spread out or thicken up but not representative of the real difference in the formations. Line was the fire formation but often infantry would form in column or mixed formation for maximum melee effect. And the type of formation really effects their fire defense especially in column where cavalry and infantry in column could be decimated by cannon balls. Maybe that's why artillery is useless because everybody essentially maneuvers in line. And always running? What is up with that?
It's a fun game but it's not historical and does not in any way depict the actual differences in types or functionalities of the units or how they were actually used in Napoleonic combat. This game is all driven by numbers. I love it but don't say it's realistic.