[glenra]

My guess is that a lot of the 17 are just adding color or confirming individual parts that don't add up to the whole. For instance, they must have had at least one source who told them about the factory with chinese-speaking workers that orders chinese pastries instead of donuts and has separate meetings/announcements for people who don't speak English. Those details help sell the article - and help create an impression that innocuous immigrant workers who enjoy delicious bright yellow pastries are some kind of nefarious 5th column - but do absolutely nothing to establish the central claim. If they had 3 sources on the donuts-and-meetings thing and include those in the 17 that only leaves 14 for the important stuff, and so on. Dial in far enough and I bet there's only one or two dubious sources for the big picture, while everyone else is in their own little information silos not knowing anything but their own part.