Why?
I know they are Jazz legends, but what makes anyone think they are great coaches? Eaton was big. He stood in the middle and blocked shots. He then tried to get down the court before the shot clock expired. What could he teach Rudy? As for Malone, it was a different era. Gobert is not going to score points by overpowering opponents and using his elbows like flying daggers. Now if Karl wants to show Rudy his bodybuilding regimen, I'm sure that would be ok. But Rudy can get that in many places. I trust the Jazz ARE putting everything they can into developing Gobert. Every coach they hired is a "player development" guy. In the off-season I'll bet he does a couple of stints at P3. Rest of the time he'll be working on strength and shooting.