Mr. Consultant, if WalMart paid you to look at their business inside and out and offer them suggestions on this, then fine. Otherwise, you're just assuming that you know more about running a business than they do, so STFU.
I'm in the consulting business. I often tell people, only half jokingly, that a consultant is a man who comes in, borrows your watch, tells you the time, and keeps the watch in payment.
Seriously, no consultant worth his salt thinks he knows more about his clients' business than his clients do. The consultant's stock in trade is knowing what questions to ask, to help the client figure out what needs to be done.