Union Artillery Fire
Confederate Artillery Fire
In the combat phase, any unit with "attack" orders can initiate combat with (attack) an adjacent unit. Any unit attacked becomes a defender as does any enemy unit adjacent to an "attacking" unit. Each attacker and defender attempts to "hit" an adjacent enemy unit a number of times equal to its Strength Points and can attempt to hit only one enemy unit per turn. A hit during the turn results in a end-of-phase Strength Point Loss and Morale Checks.
This approach seems a more realistic model of combat in an interval of time (a "turn") than allowing both sides to conduct combat (igo-ugo) in the combat phase, which is a traditional approach, and by modeling "simultaneous combat" a bit better, may not overstate casualties.