What is the most balanced methodological conclusion from these six reports?

Reports of ʿAmr ibn ʿUbayd: Attribution, Conflicting Accounts and Evidence of Criticism

• Apply general criticism to every specific report without further evidence
• Treat caution about rare reports as conclusive disproof of every rare text
• Assess attribution, hearing, teacher testimony, corroboration and chronology separately
• Automatically prefer one early audition over every later statement