Hmm..this might actually get me into AoK again....If they had better naval combat I'd take up Trafalgar. My comments are all separated by lines.
Also, British Rifles wore Green Jackets, which was what they were famous for (Besides the 400m accuracy of the English Baker Rifle).
Halberdiers for bayonets is a good idea, IMO.
smokingfrog is rght, howitzers should be bombard cannons, but don't overdo it. Bombards fire at troops, and they wouldn't use the 1:30 reload time to fire at one guy.
NAPOLEONIC WARS. Sorry.
Also, try taking up the Peninsular War, with the siege of Badajoz, and the destruction of Almeida.
The Poles were involved too; as lancers. Use frankish paladins as Polish Lancers.
The British Colonel Congreve invented a crude rocket system; maybe use a scorpion?
Fusiliers used small short guns that were good against cavalry, maybe hand cannonneers beefed up.
MY UNIT CHANGES:
Redcoats = Hand cannon
Rifles = Janissary
English Cuirassier = Light Cavalry
Hussar = Hussar
Congreve Rocket System = Scorpion
Bayonets = Halberiers
Fusiliers = Beefed up hand cannons
Polish Lancer = Frank. Paladin
Well, that's my two cents.