A single narrator can legitimately possess more than one kunya. For Ibn Jurayj, the kunyas Abū al-Walīd and Abū Khālid are both recorded.
A chain naming Abū al-Walīd and another using Abū Khālid do not therefore establish two distinct transmitters. The researcher must first verify that the respective designations are reliably attached to the same individual.
The same applies to multiple descriptions and titles. The difference between many names for one person and many persons is an evidentiary question, not a matter of counting different words.