I recently ran across a bunch of series where there are (usually two) series editors, and different volume editors (though they sometimes are the same, too). Which editors should then take precedence? The overall editors (so that the entire series will be listed in their profiles) or the volume editor (who perhaps did more work on the individual volume? ("The Cambridge Ancient History" is a good example series for this.)
The volume editors should be placed in the primary author slot, but a series editor for a series like that can be added in a secondary slot so that their profile will still show the series.
I wouldn't generally include series editors. They perform a very different function than the editor of a specific book or volume. They are usually more along the lines of an acquisition editor.
("The Cambridge Ancient History" is a good example series for this.)