I wonder if anchoring happens when multiple Steemians write about the same event or topic?

This makes me think there should be shadow guilds. The idea as that the group is made of consistent producers. Rewards can be given to individual writers or split among the group. But people who read the articles only see the name of the guild and not who wrote the article. This may would remove the anchor point if all guild members published content on the same article at the same time.