Can we have sappers in the game, small brigades max 1000 man with standart muskets and axes with ability to build breastworks and other defences one or two times per battle. price of units are 2x in comparsion with standart brigades. And maybe small pontoon too.
Usually I use 1500-2000 brigades size, but sometimes thats not enough. I use 3-4 big brigades with good melee and morale stats and with general aura for the breakthrough of enemy lines on important positions.
I found that 12 pdr whitworth is pretty good arty, because of high accuracy and very good range. And they have increased range of the canister shot, thats helps a lot.