Too early to label the FO a failure. There's enough there to retool, especially with position players. I'm not convinced there is with pitching, but that's another discussion. What to do with Polanco is a question in and of itself though. Assuming that Donaldson, Simmons and even Sano (doubtful) are all dealt, is there enough infield depth to replace an entire infield? Obviously, something that can help would need to come back in a deal somewhere. I like Polanco (at 2B, not SS), but I'm not opposed to dealing him because I do think he has decent value. Tearing down an entire infield feels more like a rebuild rather than a retool though.
Regarding Buxton and Berrios, this question will hang over this team until they're either extended or gone. However, it's an important one to answer to determine the direction of the team long term. If they're both gone, the team has further to go to reach serious contender status. There's already too much to do on the pitching side.