I’m trying to setup auto-replan of back orders for my client but got into a problem.

Based on this wiki below, the line is sorted based on Ship On date starting from the earliest one which makes sense. But why orders with the same Ship On date are not sorted based on time they are entered on that date or based on lowest sales order number? Instead, system replans based on the greatest quantity. This is a problem when order entered at afternoon with greater qty gets replanned first than order is on back order in the morning.