How exactly is trading Folty for Sale setting up for continual success? Folty could very well turn into the same 4+ WAR pitcher that Sale currently is as soon as next season, and is controlled for longer.
Anyone trading for Sale is trying to win in 2017, and they will be giving up substantial future wins to gain those wins in 2017. The whole reason the ChiSox are dealing him is because they can't sustain competitiveness with him. The ChiSox are going to trade Sale's current wins for even more future wins, thus gaining sustainability. Their gain in sustainability results in, by definition, a loss of sustainability by the Braves.
It's almost like folks don't understand the most basic concept of trades like this: future wins traded for current wins, with current wins holding the premium in terms of value.