Taking this off twitter but I think it's all right:
Marcus Smart currently has a higher 3P% than: Klay Thompson, Kemba Walker, Devin Booker, Victor Oladipo, Bradley Beal, Jamal Murray, Kyle Lowry, Chris Paul, Jo Ingles, and Eric Gordon.
I'll add that he has a higher 3P% than Al Horford, Jayson Tatum, Terry Rozier, Jaylen Brown, and Gordon Hayward.