Just use it as a ‘teaching moment’.
OK. We will confine our game to early Civil War battles (Notably, Bull Run) before the Stars and Bars were used by the Army of Northern Virginia.
We apologize to our players, if you have a hard time telling your units from the enemy’s.
Why? Because that is exactly WHY the Army of Northern Virginia started using the Stars and Bars.
Actually, it was the Stars and Bars flag that caused problems during the early battles because of confusion with the American flag, which is why the Army of Northern Virginia adopted the St. Andrews cross flag as a battle flag.