Zheng Fan held a knife, charging along with these armored soldiers. He wasn't directing anyone, unlike during the day at the Prince's mansion when he had reveled in the feeling of these elite personal guards coordinating with him.
Now, he seemed more like a withered leaf battered and swept along by the waves. He was only moving, wandering aimlessly, uncertain of what he should do.
Lord Jingnan's command, "Leave no survivors," still reverberated in Zheng Fan's ears like a clap of thunder.
This was different from Xiao Yibo. Xiao Yibo, under Siniang's death threat, had killed his own father to survive.
You might disdain Xiao Yibo's actions and his choices, but you could, at least somewhat, understand them. It was an animalistic survival instinct. Perhaps he didn't conform to human morality, but at least he could be considered a beast.
But Lord Jingnan's command was an order to exterminate his own clan!