@MartinSleziak Myshkin seems quite active, which I did not know, as mostly it happened after I left I think (and I was not all that active somewhat before either)
I should also have mentioned Stefan Kohl, which I actually did know. The editing activity of YCor is also quite extensive.
There are certainly some names there which I did not notice before.
As I said, the query might be a bit misleading, since some people can do the same thing but do not write this explicitly in the edit summary. Such edits do not appear there.
Of course, it is also possible to look at most active editors in the past week, month, quarter, year or all time. But this does not differentiate between retags and other type of edits.
It seems that it should be possible to find number of edits where tags were edited using SEDE:
I kind of get annoyed when I see users editing only one part of a question, leaving other problems stand. So I was curious to find out who our top "editing completists" are: those who have edited each of the title, tags, and body of a question. The top 5, according to a possibly terrible SEDE query, are: