Use the same Journal Monitor Group when there are multiple objects being journaled in the same journal and the entry types and frequency are the same. The journal monitor job will group the objects and will retrieve entries for all objects at the same time, to reduce the number of times the journal is accessed.
When a monitored journal is expected to have a higher volume of activity compared to other monitored journals, use a separate journal monitor group for that journal.
Lower activity journals should be combined into one journal monitor group to reduce the number of journal monitor jobs.
Due to the way the operating system caches journal information, limit each journal monitor group to no more than five different journals.