They defeated the swarm. However, the smell of the blood attracted a migrating horde, so the expedition force had to fight their way through the flood of Nightmare Creatures, as well.
Eventually, the column broke free and escaped into the vast plain, but the peace was short-lived. Very soon, they had to fight another skirmish, which grew into another battle, which grew into an unending onslaught of enemies that threw themselves on the speeding vehicles without reprieve.
The mundane soldiers fought admirably. Although not as experienced as the veterans of the First Army, these men and women had also tasted their fair share of bloodshed and strife. Everyone was calm and collected, performing their duties with deadly efficiency and poise. Their performance was immaculate, and their morale seemed unshakable.