If one person appears by a kunya in one chain and a nisba in another, what should be investigated first?

Narrator Anonymity: Wuḥdān, Mubham, Majhūl al-ʿAyn and Mastūr

• Immediately declare both chains weak
• Compare teachers, pupils, and chronology to verify identity
• Always count the names as two separate narrators
• Judge precision from the spelling alone