any these pairs? just seems too close...
The two aircraft pictures in your post #16 likely are in exactly the positions your diagram shows. Diagonally separated, not side-by-side.
Look at your diagram. Extend the |----1.5----| lines down and to the left about 15 lengths. That's about where the planespotter was when he made the picture, with a massive telephoto/telecopic lens from a ~45° angle**, that compressed the actual separation.
** note you can see both the
front of the wings and
sides of the fuselages - thus the picture was not taken directly from the side nor from directly ahead, but from 45° to the flight paths.