To reproduce, go to the steward stats, click "User groups" in the header of the table, the stewards and global renamers are still mixed in the table, rather than ordered by groups.
This is also for admin stats and patroller stats, e.g. metawiki admin stats. I cannot figure out what order it used. For me, the intuitive way is to group the users who are in the same user groups, and first sort by group count, then group names alphabetically.

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