I had originally thought of 1 + 1 + 1 = 2, but I decided to simplify it.
Clark + Superman = 1 person; 1 + 1 = 1
Another possible saying:
If you're not a superhero, don't edit my copy!
(Note: This is not a commentary on your post, Virginia. I appreciate you asking for clarification. It's just another saying I thought might be cute.)
Or, less confrontationally phrased:
Only a superhero can edit my copy.
True, it is Clark, not Superman, who edits Lois' copy, but where's the humour in that?
Joy,
Lynn