While your reasoning makes sense, there is no issue with the site functionality. Warehouse letters are arbitrary, meaning the same warehouse may be assigned different letters as you manipulate the order (quantity, items, etc.). While arbitrary warehouse A may stock the Front Right Lower, for example, it may not stock the Front Left Lower. Warehouse B may stock the Front Left Lower, so regardless of how many control arms you put into your cart, there will always be two shipping charges, unless you would like to receive multiple Front Right Lower arms, for example. If you wish to receive two different variations of the part (Front, Rear, Upper, Lower, Right, Left) the system is telling you that they are not all stocked in the same warehouse together. Thank you.