It is normally the case that a determinerless countable noun is in the plural if it functions as an object, as in "to change jobs," but the Longman Dictionary of Contemporary English has the following sentence:
We need to reduce costs, so with this end in view, the company is switching supplier.
Someone said this is an error, and the correct form is "switching suppliers." But is this an accidental error, or is it intentional? If it is intentional, are there any other similar examples? Also, if "to switch supplier" and "to switch suppliers" are both correct, what makes them different from "to change jobs"?