Years ago I used to offset them because it was thought that they could catch and interfere with each other and cause problems. I lost a model once when the controls locked up in the outside loops and could find no other cause after looking through the remains, and thought it may have been the leadout connections hanging up. But as time went on, it seemed to be kind of a pain, especially when winding the lines up, or shortening lines and such. I retrospect, if they do interfere with each other, it may be because the leadouts are way too long. It seems like these days my leadouts have more separation as they leave the wing tip and leadout guides, as I try to have individual adjustable leadouts. And there are the reasons Brett stated that are good enough by themselves alone.
Type at you later,
Dan McEntee