Personally, I believe in Niang as someone who can play in the playoffs. He's one of the few guys on the roster that showed some understanding of defensive concepts outside of being a statue. His shooting was awful, but I believe in his entire body of work over one playoff series. You absolutely need guys to knock down open shots in the playoffs and I trust that he can be that guy. Defensively, I also trust him to give us more than Conley, Mitchell, Bogey, Clarkson, and maybe even Ingles at his age.
To me, Bogey+Clarkson is luxury we can't afford to have. Both provide little to nothing outside of scoring. IMO, the value that having both gives you is insurance when someone is injured, but the Jazz aren't winning the title they aren't healthy anyways. It makes sense to move one of them for a more versatile player. Having all these scorers/ballhandlers in surplus is a RS bonus, but not so much in the playoffs.