मन्त्रिभिस्त्रिभिश्चतुर्भिर्वा सह मन्त्रयेत ॥ कZ_०१.१५.३४ ॥
mantribhis tribhiś caturbhir vā saha mantrayeta
He should deliberate with three or four ministers.
It balances two objectives: enough diversity for sound judgment, yet small enough to preserve secrecy and control coordination.