Regarding the "Chinese sold as Murano", there is another very good reason for some of the misattributions. Many examples have appeared over the years with a sticky generic "Murano" label.
So, if somebody sees examples of those and they have a very similar, but unlabelled item, it's quite reasonable that, without any evidence to the contrary, they would believe them to be Murano.
I corresponded with an American eBay seller a few years ago who had listed several such weights with a Murano sticker. I sent copies of images from a Chinese trade catalogue which showed the same type of weights and one in fact (with a "double overlay" finish) was absolutely identical, but missing the original Chinese wooden base. It was said that those weights were sourced via a German dealer.
But Frank's point is also valid - it's often a case of giving something a name based on just a broad similarity to something seen elsewhere.