The USS Cumberland is listed as a steam frigate, it was a small sail frigate.
The Union unit box 'Iroquois' has one ship the Iroquois, the unit box 'Richmond' has one ship the Iroquois, this should presumably be the Richmond as i have not seen the Richmond elsewhere.
Many units are questionably rated, there were, what, only 6 or 7 steam frigates in the US navy in '61 including the Merimack.
The Richmond, Hartford, Brooklyn etc were screw sloops (a monumentally bad name since they had 3 masts) with 10 guns or so. They had much less draft than the steam frigates which couldn't get near a river.
Also, the Confederate ironclad Manassas maybe should be a tinclad as it had one 32lb cannon, a ram, and one inch of armour. Hardly the Tennessee.
The USS San Jacinto is a screw frigate, not a sail frigate but i thought you may have her listed as a sail frigate since she was the slowest screw frigate in the navy, so this might be on purpose on your part.
Way to many 10lb parrot rifles in the early war for both sides. There are a number of '61 stacks for both sides where all of the guns are 10lb parrots. the vast majority of these should be 6lb or 12lb smoothbores. I am assuming 12lb howitzers are subsumed into 12lb smoothbores? I think at Bull Run, for example, the Confederates had one rifled gun. And, who was it, John Imboden? who said the Union rifled guns were accurate, and long range but the fuzes did not go off until the round buried itself in the dirt.
Hope some of this helps,
Michael