HD usually does things right but....
Central ized buying does have some problems. For instance, the Tampa, FL buyer (or wherever it was down south) is as ill equipped to buy snow shovels as the Chicago buyer is to buy pool supplies and garden equipment year round.
Also, since we know that many buyers, although not all, are in the habit of taking "gifts", the larger volume of purchases from a central buyer enhances the product line buyer's power and thus his (or her's) ability to receive the gratuities. The anti-kickback squad has to be on their toes.