But you are overrating the prospects dealt, otherwise why would you still be bringing that trade up as some sort of "what if" scenario? If you actually evaluate those prospects AT THE TIME OF THE TRADE: Martin was showing no defensive value and was not hitting well in AA, all he was doing was drawing walks and swinging a noodle bat. Keith Law was CONSTANTLY stating that SWR's upside was that of a reliever, and this was at the time of the trade. If you remember, he was struggling heavily and his stuff was down. Both players fell out of any Top 100 prospect discussion. Again, this was at the time of the trade. If the website writers were coming to these conclusions, I highly doubt that actual teams were seeing "star prospects" in either of these two. Martin in particular seemed to be getting far too much benefit of the doubt, as if people were afraid to "write him off" despite the fact that he was showing very very concerning issues for a supposed "elite hitter".
So you don't even need to look at the prospects "in hindsight", because what you see now is basically the same or worse to what was seen when they were actually dealt. SWR was doing much better in AA this season and was recently promoted to AAA, but I just looked at a Twins forum out of curiosity and some of the reports suggest that he's been ~88-91 with his fastball this season. Everything else still looks the same: concerns relating to his delivery, and a breaking ball that flashes above average, but seems to be too easy to pick up out of his hand. From the Twins perspective, it really looks like they got a ~#5 starter and a utility hitter with no power who can't field any position better than average for 1.5 years of Berrios, who at the time was still a ~3+ WAR starter.