It's the same rationale for Xichuan Prefecture: after recapturing the old territory of Xichuan Country, the new Xichuan Prefecture borders directly with Nanzhao, a great enemy to the south.
With Nanzhao's national strength, they can mobilize a 100,000-strong army at any time for long-term warfare. With desperation, raising an army of 300,000 is not impossible.
Such a great enemy must not be underestimated and ignored.
To Xichuan Prefecture's north, although there is Hanzhong Country, it does not pose much of a threat.
But to the north of Hanzhong Country lies Zhou Country, an enormous force. To prevent Zhou Country from breaking through Hanzhong and brazenly marching southward, Xichuan's northern border must maintain adequate defensive forces.
Thus, within Xichuan Prefecture, there must be at least two, or even three, Forbidden armies, along with an Inborn Grandmaster stationed there.
Adding these two prefectures together, five Forbidden armies will be required.
