The Cubs have a stockpile of high-end position prospects and the Marlins have a long list of fine young pitchers. Prospect-for-prospect deals are rare because they require a strong stomach. Needless to say, such trades carry a big risk.
The Cubs have four huge positional prospects in Kris Bryant, Javier Baez, Albert Almora and Jorge Soler, while the Marlins' list of young pitchers is quite impressive. Beyond Jacob Turner, Nate Eovaldi and no-hitter man Henderson Alvarez who all pitched in the majors this past season, Miami has Andrew Heaney, Justin Nicolino, Adam Conley, Jose Urena and Brian Flynn, among others.
Presumably the Marlins would be most interested in Baez and Bryant since they are infielders, though Bryant may be nearly untouchable. Miami has a decent stash of young outfielders, though Almora, who is from Miami, might be interesting. Last year's draftees like Bryant, the No. 2 overall pick, aren't eligible to be trade until June, too.
The Cubs' pitching list is improved, but there's still a gap between the quality of its top young hitters and pitchers.