I'm not sure I would be happy with this deal. I really love Butler, but I would want to put him next to Crowder at the 2, not have him replace Crowder at the 3. Jimmy is most effective at the 2 because he can bully smaller defenders and draw fouls, that doesn't happen at the 3.
However, if we had any chance at a Durant then trading Crowder for Jimmy makes more sense.
Personally, I think that Durant would be more interested if we can add Butler or Love and Horford, but I think the best we can do is come in 2nd. I expect Durant to go back to OKC for a year then we could have a chance in 2017.
If something like this happens, then I will give all credit to this guy, but for now i'm skeptical.