MS
1%er
A few days after the trade, Kevin Gausman was waived by Atlanta. Gausman has struggled less than Sanchez this year and has a significantly better track record the last few years... and his value was basically nothing.
Since he was permanently removed from the rotation, Biagini has a 4.50 ERA and a 4.92 FIP in 116 IP. He's improved this year to the point where he's on pace for about 0.3 fWAR.
I liked them both and really hoped they would figure it out, but it seems like your evaluation of them is based on a combination of what they used to be and what you want them to be. In reality, both of these guys were really good in 2016 and both of them have been awful for three years now.
(For the record, I also hated that Stevenson was thrown in. Given the trade as a whole, I would have been perfectly happy with it if a Stevenson-calibre prospect was coming back to the Jays instead, so that part bugged me more than anything. I think it was a bad trade, but you have to be unreasonably high on the Jays guys and unreasonably low on Fisher to analyze it the way you have.)
Throwing a decent prospect in is the biggest thing for me. We agree there.
Biagini is at 0.8 bWAR this year. He's a useful pitcher.
Sanchez and Gausman aren't the same thing. Sanchez is 27 and less than 3 years removed from an ERA title. And has then battled injuries since. What he showed in 2015-16 still gave him a bit of value in spite of his horrible season this year. I'm not disappointed at all he was traded, and even if the trade was Sanchez-Fisher, fair enough. The problem is the piling-on of assets to get a guy who quite obviously isn't very good.