Zhou Tian did want to seize more territory in one fell swoop, but he was well aware that despite the deterrent effect that the Beastman Archers had on the Tiger Tribe and the Werewolf Tribe, if those two races were truly pushed into a corner, they might well retaliate. If they did, Zhou Tian was not worried about his own defeat, but even if he managed to repel the two monster races, his own strength would not emerge unscathed from a desperate fight. If his power was weakened to a certain extent, he believed that his other neighbors would not miss the opportunity to invade.
So, now that he had gained an advantage, Zhou Tian naturally did not mind quitting while he was ahead. After all, he already had a large swathe of unoccupied territory. Once he had assimilated the newly seized territories, when he wanted to expand his influence again, attacking the Werewolf Tribe and the Tiger Tribe was merely a matter of words for him.