Some titles resemble other words unless their vowels and consonantal dots are recorded precisely. Misreading a title can obscure a known transmitter or merge distinct people. Biographical research must therefore determine not only the form of a laqab but also its bearer.
Knowledge of the personal names behind titles is a distinct task in narrator identification.
For example, deciding which individual is called al-Aʿmash requires his full identity and the context of the chain. A shared title cannot replace the study of his teachers, pupils and chronology.
Nor does a descriptive title by itself establish the moral standing or accuracy of its bearer. Those are evaluated through independent critical evidence.