All good points, Dawger. Jappa and I most frequently see the "Girl Scout formation" as you call it (and aptly so). I think that will be our new term instead of "in trail".
You are absolutely right. Mutual supportive formation is essential for survival and success in any engagement. For instance, in this screen shot, it's pretty clear who has mutual support and not.
As you term it, the "Girl Scout formation" isn't working well here. Well, maybe for the guy right behind Jappa until he runs outta grapes behind him.......