I know it has been also asked for UG:G but i don't give up to have pairs of flags for units, both star and stripes and regimental flag. Imagine the sons of Erin with the green one or South Carollina rifles with their blue banner
In relation to uniformity, Why not different hats for Iron brigade or at least different colors for their top hat? Zouaves could be very easy to display; only red pixelation.
And for arty, If you can see different cannons and colours in the barracks , why not see them on the battlefield?