What is the authenticity of the narration of a Hadith scholar who refers to men from Sindh by saying, "The trustworthy one narrated to me"?

Scholars have differed regarding the acceptance of amending the anonymous (mubham). The majority of them are of the view that it is not accepted, while Abu Hanifa accepted it. The more correct view is that it is not accepted, because the anonymous person might be deemed unreliable by someone other than the one who amended him. It is reported that Al-Shafi'i and Malik said: "A trustworthy person narrated to me," and this is acceptable if the anonymous person is identified by an indication (qarinah). Abu Hatim mentioned examples of how Al-Shafi'i identified those he made anonymous.