Small suggestion: Could we possibly increase the unit size of Grenadiers to the same as line infantry? Their elite status is often outweighed by their numerical disadvantage.
Also, bayonet charges seem very ineffective, maybe it's just the faction I'm playing (France) but something about it just seems off. For instance, I had three units (Two grenadiers, one Fusiliers of the line, each with one experience chevron) charge the flank
of a single unit of enemy line infantry (Prussian Musketeers) while they were in a firefight with another of my units, making them unable to turn and fire. The result: all three of my units suffered heavy casualties and my line infantry routed. I immediately rage-quit.
The other problem with melee is the A.I.'s stupid path-finding (i.e. charging in at the wind instead of at the enemy) but I know there's nothing you can do to fix that.