Reason for grand battery

What ist the big advantage for a grand battery, because each involved artillery cost an order.

I only think about more dices and therefore more flags as a bigger chance for a hostile retreat. Because of  range fire there is no need to addition the dices to destroy all units at once with one throw. I can use one gun after another as well.

Thank you dondiring

it is exactly that, all the dice simultaneous. The flags are all at once, meaning retreats can't be ignored, and if the unit cannot retreat, more hits.

even if the unit can retreat, it is sometimes worth rolling all the dice at once to try and eliminate the unit in one blow, rather than rolling a flag on the first roll and seeing the hoped for banner hide behind something

Thank you!