If what happened in Toronto has no bearing, you are complaining about trading a pitcher who would a free agent 3 years ago. You can’t say he would have signed here by your parameters.
So you point out his ERA in Toronto is exactly the same as here, which is within hundredths of the same ERA as SWR. Berrios good years are better, his bad years are worse. So if over a career the outcome averages out to be the same you have no argument.