चत्वारो दुर्जयः ॥ कZ_१०.६.२२ ॥
catvāro durjayaḥ
چار دَنڈ مل کر “دُرجَیَ” (جسے فتح کرنا دشوار ہو) کی ترتیب بناتے ہیں۔
Redundancy and depth: multiple mutually supporting units reduce single-point failure—an administrative logic applied to battlefield organization.