wedge, spear and shield soldiers at the edges, the cavalry, archers, and supply wagons inside."
-Jerry Pournelle, King David's Spaceship (London, 1984), pp. 185-186.
Such a small disciplined wedge is able to sally forth from a besieged city, out into the midst of vastly greater numbers of besieging barbarians, to kill the besiegers in great numbers without being overwhelmed by them and to return to the safety of the city. The above link to a post about a Poul Anderson heroic fantasy novel reveals that, mythologically speaking, it was Odin who taught this military formation to mankind.
Am I interested in learning military tactics? Personally, not very. However, as with the seamanship in Chapter Twelve, it is always interesting to read an account of skilled activities by a writer who understands them. And it is good to see the demoralized men of a besieged city win a new kind of collective confidence.