The chief benefit of mutaba‘ah is corroboration. Agreement among genuinely reliable and sufficiently independent routes may reduce the likelihood that one transmitter erred individually. Different-looking names, however, do not prove that two accounts are independent.
Examine the supporting chain's reliability, the accuracy of its transmitters, its shared source, and any differences in wording. If both accounts merely reproduce one underlying mistake, the second does not cure the first. Nor can a highly defective or contradictory report be promoted by simply labelling it a follow-up.
Conclusion: a mutaba‘ah is an item of evidence; the degree of strengthening depends on the actual quality and relationship of the routes.