How to improve "second/third party source as artist tag" situations?

Second/third party sources sometimes get mistake as the artist. Usually I tag the posts with the corresponding party tag, add artist request and delete the wrong artist tag. But I just found that there're a lot more of these "artist" tags out there, and it's especially severe with Weibo sources. (1, 2, 3
It makes me wonder if there're better solutions dealing this? Other than throwing them in the artist request abyss even when their source has something in common and the artist will probably never be indicated anyway. Or how to prevent this from happening? Or just any general improvement?

This is definitely problem, in some cases I encounter some weibo posts that post a cropped version of a illustration, and not quite citing the artist either. I also encounter a few issues when they do cite a user in which their account doesn't exist/deleted, or the person they're referring to doesn't really post any art. It makes so I'm not very certain of who the artist is sometimes. I have to make assumptions sometimes if they're not citing an artist, then it's likely the original source.