It seems very difficult to replicate one of the key operational innovations which Napoleon pioneered (and which was later copied) - the Corps system. While the command structure definitely gets half of it right in terms of allowing (and encouraging) you to form these mini-armies, you are then very limited in telling them what they can do.
If the scale were lowered so that there were more regions, then you could "move divided and fight concentrated" as Napoleon historically did (or didn't, as the case may be). Currently that's impossible since the physical location of each Corps is so homogenized. Basically, you just cram them all into the same region, synch their moves, and that's it. The Corps System is thereby reduced to being a purely administrative utility, while largely ignoring the fact that they were also independent *maneuver* units.
As an example, just try to: use one corps to hold the enemy and then have the others converge from different axes of advance. This is the famous "manoeuvre sur derriere" which won Napoleon's biggest victories. But you can't do it with this system. Instead, the entire army advances and, effectively, attacks the enemy frontally. Where's the artistry in that?
By depriving you of the best tool in Napoleon's arsenal, you are reduced to (effectively) fighting Borodino over and over.