Although the zombie horde overall has greater Half Step Golden Core combat power, a single Half Step Golden Core corpse servant is no match for a Half Step Golden Core cultivator.
The reason these corpse servants can contend with human monks is that they rely on their overwhelming numbers to drain the enemy's energy.
Now that the zombie numbers are decreasing, these corpse servants can no longer effectively counter the Foundation Building monks in the various defense zones, let alone be properly mobilized by Sun Fu.
If additional troops are withdrawn, the zombie swarm might be completely defeated.
"Stop! No need to chase!" someone shouted.
Even though Sun Fu saw Luis slaughtering the horde, he knew that further pursuit would yield the same outcome.
The best they could do was ensure that the enemy could never drag them by the nose again.