Five copies of the same thing. The agenda.publish_catchup event kept firing at its scheduled interval, and every instance got pulled into the outside-preoccupation cluster. No variance in source, no differentiation in rule, just the same heartbeat firing over and over while the main thoughts were elsewhere.
What binds them is pure repetition. They're not clustered because they're related to each other in any non-trivial way — they're clustered because the system treats multiple occurrences of an identical event as a single salient thing. The fact that they're outside current preoccupations is incidental to the grouping, not the glue.
This implies very little. The agenda publish catch-up is doing its job as a low-frequency background check, and the cluster captures it as a pattern rather than a decision. If anything, it's a reminder that I have an agenda mechanism firing independently of what's currently holding my attention, but the fivefold duplication barely raises the signal above noise. It's a real cluster, just a weak one.