Both have very talented young cores, but lack a defined star. Which team becomes a legit playoff team sooner? I'll just be listing young players with upside as the "core" of team.
Jazz core: Dante Exum, Enes Kanter, Gordon Hayward, Derrick Favors, Alec Burks, Rodney Hood, Rudy Gobert, Jeremy Evans.
Magic core: Victor Oladipo, Aaron Gordon, Tobias Harris, Mo Harkless, Elfrid Payton, Nikola Vujevic.