If a player is to become one of significance, no matter how raw they are, I'm a big believer in seeing early glimpses and we've seen some of those in his case. But between the extremely loose handle and the non existent jump shot, I can't remember a PG like this being successful and the fact that he's shown no improvement in either area 16 months after being drafted doesn't inspire confidence.
Smart, Carter-Williams, Dunn, Mudiay, Payton, Exum, are all recent examples of hyped PG's who struggled in at least one of these areas (all were at least willing jump shooters though) and right now Payton is the only starter and he's a low end one at that.
His play making is better than advertised, but he doesn't have the vision of Wall, Rubio or Rondo. He's athletic, but not to the extent of Westbrook, Wall or pre injuries Rose, so what is he? And does it make sense to spend a good portion of Leonard's prime and the remainder of Aldridge's, finding out? Worse yet, does the lack of so much as a competent starting PG become the impetus for Leonard not re-signing?