The value of additional transmission routes depends on the nature of the weakness. Some deficiencies permit corroboration to lower the probability of error: for example, uncertainty about a mastur transmitter or a narrator whose precision problem is not severe.
A chain built on a proven fabricator, or a report marked by serious established irregularity, does not receive the same benefit from numerical accumulation. Nor does another route retroactively make every original chain intrinsically sound; the improvement may belong to the report as supported by its combined evidence.
Example: Two genuinely separate routes with compensable shortcomings may reinforce the same content. If both simply reproduce one fabricated source, they are not two independent proofs.