Poeltl is a solid starting Center which Boban is not. Second Anunoby and Siakam were never really in play, also this story gets old. You can get an Allstar and a good Young Player or nothing.
As the Season progressed, Aldridge and Poeltl played better and better together. What Poeltl lacks is a decent midrange Shot, which can be worked on. Not every player needs to be a 3-Point Shooter.
Everything Else Poeltl is already what you need: Able to defend the Perimenter decent enough, shot blocking/altering shot, rim protection, efficent finishing around the rim, great offensive rebounder (defensiv could be better), one of the best screen setters of the league, high Basketball IQ, good lockerroom guy, the defense of the team is much better with him on the court. Can defend one on one against better bigs. There are not many non All-Star Center who can provide that at the age of 23 and he only is getting better.