In Lyon most of the sales assistants are quite smart. Unlike many American sales clerks, they can actually help you, at least when they choose to. There is not much unskilled labor walking around the typical FNAC store.
But this is a mixed blessing. A clerk will spend half an hour "helping" a customer. I wait and wait. (It is worse than the Falls Church Public Library.) I do not understand their conversations. Did in fact Sartre grasp Heidegger’s critique of phenomenology, and what does that mean for the purchase of a cell phone? The question has not been resolved.
Customers cannot talk for so long to a stupid person. So if you know what you are doing, you might prefer that the sales people be stupider. Stupid people will spend more time, in percentage terms, helping the already informed.
"Batteries are over there." Even a stupid person can manage that.