I concur with this analysis at the amino acid level. I would add, however, that even if two virus isolates have an IDENTICAL amino acid sequence, that would not automatically make one the origin of the other. In my post 10 days ago, Tackling Rumors of a Suspicious Origin of nCoV2019 , I showed that mutations in the 3rd wobble base in an otherwise conserved region accumulate as to make seemingly identical viruses very much separated in time – indeed over decades.
It is time to leave playing “who’s ur daddy” to daytime television. No known viral RNA sequence is the daddy of SARS-CoV-2. No match. If it doesn’t fit, you must acquit. It is all bat guano. Whatever analogy you like. A thrust of distrust and recrimination is not the path to protecting the planet from a viral catastrophe.
Bill Gallaher