First, the defensive strength of the player's main city was undoubtedly strong, even if it was unnecessary most of the time, yet the player's main city was still built on a scale equivalent to, or even surpassing NPC main cities. And with the defensive strength of that city, whether it was monsters or NPCs defending with their strength, it wouldn't be a problem to resist an army several times their own size. And with such defensive power, not to mention that the lower-rank strength Zhou Tian currently held the upper hand, even if the strength of the smaller creatures was at a disadvantage, that city's power was more than sufficient to ensure that Zhou Tian's subordinates would not be defeated by those lower-rank NPC armies and players.