The scene where Orlandu and Goltana discuss the 400,000 casualties doesn't mention where the battles have been fought. The scene before mentions troops marching on Lesalia and Bethla Garrison. Since it's not the Garrison, I'm going to go with Lesalia.
BTW, I mentioned Bethla Garrison because Ramza and allies are fighting their way toward the Sluice Gate to stop the larger battle in the valley.
