Treating “X ibn Y” as one undivided label conceals many possible confusions. Record the narrator’s name, the father’s name, and any nisbah separately. Compare each part: Is the first name identical? Does the father’s name differ? Is the difference written, spoken, or both?
Illustrative pair: “Muḥammad ibn Sinān” and “Muḥammad ibn Sayyār” share “Muḥammad,” but the fathers’ names are different. Identical given names cannot establish personal identity without examining the patronymics and their reading.
Teacher-pupil relationships are then used to decide whether the apparent difference is a matter of pronunciation, a distinction between people, or both.