I noticed today great similarity between my Profile Impact summary on History.StackExchange
and on Stack Overflow itself
The coincidence of both Posts Edited and People Reached being the same number despite the vastly different activity I have had on the two sites seems more likely to be a query error than reality.
By my count the number of edited posts is way low on both counts. I estimate nearly 400 edited posts on Stack Overflow (20 pages @ 20 / page) and about 740 for History (37 pages @ 20 / page).