Numerous routes may have much less collective value if they are all affected by a single serious defect, or if their transmitters fail the relevant standards of reliable reporting. Quantity cannot simply substitute for quality.
Narrator weakness concerns competence, accuracy, and trustworthiness. A hidden defect (ʿillah) can be a subtle problem in an apparently acceptable chain or text, discovered only through expert comparison.
Therefore, “the report has several routes” should trigger further questions: Are they independent and sound? Do they share a defect? Are there significant conflicts in wording or meaning? These determine whether the multiplicity is truly a corroborating indicator.