One team winning a trade doesn't mean the other team lost. I think this could turn out to be a trade in which both teams end up winning. If Diaz becomes a borderline AS at 2b (I think he can be that), Yamamoto is a steady #3-4 SP going forward, and Harrison OR Brinson become everyday CF with at least passable offense (all of which I think are quite possible), it is hard to say that Marlins aren't better off. Christian Yelich in Miami wasn't Christian Yelich in Milwaukee. There's no guaranteeing that he would become what he is had he stayed there. And even if he had, he's far more valuable to a contending team like Milwaukee than a rebuilding franchise like Miami.