Forming squares should not be based on a brigade commander's stance. It should be based on the threat danger of the cavalry. Even the Guard marched to the British lines in square and that was an all out attack.
Is based on the cavalry danger but in order to act it has to have a stance: all out attack is a stance situation, only neutral or TC\player controlled officer are a no-stance situations.
What determines the brigade stance?
the stance-id value of TableTacOrders + the stance modifier of unitattributes.csv + a random value between -100 and 100.
>What role does the division commander play if he does not determine what his brigades are to do?
When not in a fight it determines the brigade destinations on the base of own proper objectives, when in fight it assigns the Play, so it assign them a place along the line and a Order (hold to the last, --- all out attack, which generates or change a stance) to every brigade.