Can you post the query you are using to pull this data? It will also be helpful to know which version of jive you are running. I took a quick look at our primary instance and our 40’s (modifies) on 2’s (messages) are only about 11% of the 20’s (creates) on 2’s.
I would also recommend investigating the metadata & user_id fields in jivedw_activity_fact for the modifications to see if it’s a normal user or not. Might also want to look at the timestamps if things are happening within milliseconds it’s probably not a meat person making the action.