Battle Two Results Question

[Wheat]

In this battle, McCullough attacks with about 15000 men or so. His force is moving into the region with Bowling Green, where Grant sits as well as a force under Confederate General Cheatham, of about 15000 men.

Cheatham is set to defensive posture in his entrenchments. The battle shows 30000 Rebs attacking so that must count Cheatham's men. The Rebs lose, Cheatham retreats out of his entrenchments to an adjacent region, but the battle results show NONE of Cheathams units or commanders involved. Why does Cheatham retreat if he was not involved in the battle?

[Captain_Orso]

McCulloch enters the Bowling Green region is OP (Offensive Posture) and commits vs Grant. Why Cheatham doesn't join the battle I cannot say. Maybe because the battle was over before he could be called up.

After a battle I believe all stacks in the region are subject to a retreat check. Per chance this probably caused Cheatham to retreat. It's not seldom that stacks which were not involved in a battle retreat, but I've personally never seen a stack larger than the remaining enemy force retreat, that I can remember. I would chalk it to bad luck.