I found this video on a forum, and some lively discussion.

What are your thoughts on the formations used in this training excercise, etc.

[youtube=http://www.youtube.com/watch?v=1Qe_8JNAXVc]

It demonstrates in a modern context the Phalanx/Cohort tight formation versus the rabble style loose formation and its ability to drive and maneuver. I can imagine the, Celtics and other Gaulish Germanic tribes functioning in battle in a similar vein.

Lacking here of course are Leadership, casualties and a a desire to win by the ‘rabble’