I don't like the mob thing either but it's how large group dynamics on the internet work (by default). We try to mitigate it where we can but there's not a lot of knowledge about how to do that.
From then on, whenever a user takes an action on the site (posting, commenting, voting, flagging, etc.) they are prompted to provide an explanation as to how their action contributes to the community. All actions and their transparency notes are stored in this log.
Make it so that it can be skipped, but where applicable the action is delayed, marked with a sigil, and down-weighted.
Ideally this would be a moment to think about whether the contributions meet the guidelines or otherwise move discussion forward.
Edit: to be perfectly clear, I’m asking people to justify their contributions.