Lei Buji's response was beyond what the Niu brothers had expected.
By all accounts, there was no significant enmity between them, and overall the Niu brothers treated them with courtesy. Additionally, the situation was clearly in the bandits' favor… To rise up and challenge under these circumstances, one would either have to be obsessively principled or a reckless simpleton.
Of course, one could be reckless if they chose, but then the Niu brothers' carefully prepared script couldn't be carried out.
The stratagem of Tang Banner Master was well-conceived—
The first step: Keep three men to stay overnight, which wouldn't require much—a single night would suffice—but their rooms must be arranged not too far from the prison cells.
The second step: Host a grand banquet at night, where both village chiefs would pretend to be dead drunk and the night watch of the stronghold would deliberately slacken.