The problem is that the league has figured out how to beat the Jazz. Any team that plays a mobile big, stretch-5 or small-5 can move Rudy out of drop coverage. Then the rest of our guys get exposed defensively and can be hunted for mismatches. Jazz can tell these guys to play harder on defense, but they're limited in what they can do.
One solution to this that wouldn't require wholesale changes to the roster would be to bring in a secondary rim protector who can rotate down when Rudy gets pulled out. Maybe Rudy Gay fits that description, not sure. Otherwise, this would be a Jerami Grant or Christian Wood-type player at the 4. I keep hearing rumors that the Rockets would be willing to trade Wood, and I'm assuming they want picks.
The ideal guard to pair with Donovan Mitchell would be someone who can play both on and off the ball on offense, but who can also guard switches. So that would be more the Shai Gilgeous archetype than the Mike Conley or Jared Butler archetype. From that perspective, Desmond Bane would have been a good pick for the Jazz in the late 1st round a year ago. I can also see why the Jazz tried for so many years to make Dante Exum successful. If he had panned out, he'd be ideal next to Mitchell. Nonetheless, Conley is very good and the Jazz love him, so he's not going to move. If the Jazz had someone like Derrick White in their rotation, I think they'd still play him as the 4th guard in their rotation. It's more likely that the Jazz will try to make a fix on the wing.
With Rudy pulled out of position, the guy that gets exposed the most defensively is Bojan. He was getting killed in pick-and-roll coverage by Kyle Lowry, and guys like Duncan Robinson and Tyler Herro were easily getting a step or two on him to create open shots. Against the Nuggets, Aaron Gordon destroyed him in isolations and post-ups. Bojan is just a limited defender. Good coaches know to go at him and put him on an island. I'm not sure what to do about him tbh. He's like our version of Carmelo.
The other thing teams do against the Jazz is switch 1 - 5 on defense. This stymies the Jazz's ball movement and exposes our system players, which include Joe and Royce, as they can no longer score or move the ball well. The solution here would be to replace one or both of them with a more effective 2-way wing. The pie-in-the-sky archetype here would be Jaylen Brown, which obviously won't happen. The problem is the entire league is hot for 2-way wings, and I'm not sure what the Jazz can get here. The value of guys like Miles Bridges, Mikal Bridges and Keldon Johnson is through the roof. This again is where Rudy Gay can make a difference. The expectation is that he can make an impact defensively and also put the ball down and attack a switching defense on offense.
If Rudy Gay can prove himself as a help defender on the floor next to Rudy, and if he can prove his ability to make plays offensively against a switching defense, then I think you're going to see Gay take some of Bojan's and Royce's minutes against teams that know how to exploit the Jazz. Otherwise, I could see Bojan or Joe getting traded by the deadline.