I figured it out through physically acting it out in a rehearsal for my ballet studio's Nutcracker production... All of the dancers playing "soldiers" were told to form a size-sorted column with tallest in the center, then march in sync counter-clockwise to rotate it a quarter-turn. So the kids nearer the middle almost were marching in place, while way the eff out at the column's edge, I was taking the biggest "march" steps I could manage just to keep up!