Of course, dealing with an opponent like Zhou Tian, such tactics wouldn't actually have much effect. But given the battle situation they were in at the time, without any accidents, then with the True God's tactics, even if Zhou Tian was unharmed, his subordinate deities would find it hard to escape the opponent's poisonous hands.
And if Zhou Tian had just left his subordinate deities behind, even if he himself remained unharmed today, outsiders would likely still see him as having lost.
It's certain that Zhou Tian didn't want to lose to the True God. However, given the circumstances, even if he was unwilling, there was little he could change.