Costs of shipment with method shipment may create order shipment cost
Sales with shipment cost method on order check if all shipments have been done to invoice the cost. But with the migration of #10774 (closed) we may have shipment with cost method being 'shipment' even if they were created by a sale with 'order' value. This results with the cost being invoiced twice.
There may be other cases where the cost method of a shipment is different from its sale order.
So I think the sale should only consider shipment with the same cost method to decide to invoice or not.