The tiny opening in the northern front had given the Martian united front an opportunity to wage a counterattack. The goal of the counter was not to defeat Zergs; instead, it was supposed to be a strategic show of strength, hoping to keep the pressure on the latter.
The Zergs wouldn't have understood the concept of pressure before the dark ones were born. The primitive Zergs hardly ever thought about battle tactics, since they lacked both intelligence and emotions. Timing was the key in implementing any military tactical moves, and Wang Tong's task was to provide such opportunity for human resistance.
While the Zergs were turning the world upside down in trying to find Wang Tong and his retinue, the human warriors didn't just hide in a cave— not like there was any cave to hide from the get-go. Instead, they turned around and tried to stay ahead of the Zerg search parties. However, they were still too slow.