I was at the game last night. Here are a few comments...
NWG: The Jazz just brought him over from Europe. He can do the things that Neto did for us. He plays decent position-defense, can hit some open shots, and can credibly drive to the rim and finish without getting injured. He's fine for a 3rd-string PG, and he'll make the roster.
Bradley: He has gravity at the rim, he rebounds as well as Kanter did at the same age, and he's a credible roll-man who can catch and finish efficiently. He's fine as a 3rd-string center. He'll get exposed a bit guarding out on the floor, but against back-ups it shouldn't be too big a problem.
Oni: He is already a multi-positional defender, an adequate corner-3pt shooter, and an athlete who can fill the lane and finish at the rim. He's not going anywhere. He's a steal for a late 2nd-round pick. If he could dribble and change directions, he'd have star potential. He's going to be a text-book 3/D wing with plus speed and athleticism. He's smart and disciplined, perfect for the Jazz's system, and he's better than Royce was as a rookie.
Where the Jazz have a log-jam is the 3rd-string PF spot, where we have Niang, Kidd and Howard. The Jazz can keep two of these guys and play one of them as a 3rd-string SF. That's why both Howard and Kidd were on the floor together last night. TBH, I'd like to see Brantley in that mix as well, but the Jazz can develop him in the G-League and give him a few assignments with the Jazz if they want.
Howard: He's really a wing, so think of him as the 3rd SF. He's not used to the speed of the NBA game, and he needs to work on his strength a bit. He likes to hang out on the perimeter for catch-and-shoot opportunities. He's a knock-down shooter with an easy, smooth stroke out to 28 feet. He keeps his composure and shoots well under game pressure. He was 3/3 last night and hit from multiple locations around the arc. Guys were passing up shots to get him the ball. I also liked the way he attacked a close-out and finished with a reverse lay-up. The Jazz bought out his contract in Europe, and even though it isn't much, I'd be surprised if they cut him.
So to me, the question comes down to keeping Kidd or Niang. The problem with Kidd is that he's an inconsistent shooter. If he shoots a 3, I expect it to miss. If he'll defend and rebound that makes up for some of it, but I'm not sure how consistently he does that. The problem with Niang is that he's a non-athlete by NBA standards. That limits his defense, rebounding and play off the dribble. He's a smart player who knows the system. He's a better shooter and passer than Kidd, and that will probably make the difference.
Probably Kidd is the guy who gets cut, and the 15-man roster would look like this:
Conley / Mudiay / Williams-Goss
Mitchell / Exum / Oni
Bogdanovic / O'Neale / Howard
Green / Ingles / Niang
Gobert / Davis / Bradley