Unless I’m just incapable of interpreting the information, it seems to me that the participant list for an event does not clearly indicate who of the Leaders and Sweepers have actually signed up for the event — it just lists everyone who is marked for the role in the event settings.
This feels like essential information, especially for those in those roles. IIRC this used to work, something around the Clubs functionality or maybe how Friends are listed is causing an issue here?