Back in the days of Titanic Tuesday and hugely populated weekends you would see outlandish kill totals landed.
But only by a small minority of players, who were able to fully exploit the 'fish in a barrel' situations. I did myself some stunts like 50 in a Tempest (rearm), 11 in a Hurricane 1 with and 6 or 7 without rearm. I wouldn't be able to do anything like that in today's arena, not only because I've gotten older and slower, but also because I could not find enough appropriate targets anymore.
I remember running some analysis about landed kills back in the day. Turned out most kills weren't even landed with an arena 'landed X kills in' message (either because the pilot had just one, or died). And the broadcasted landing messages had mostly been 2 and 3 kills type - but the outlandish ones are those getting all attention and thus getting remembered so well.
The average Joe still had a success rate quite similar to the one I posted earlier,