Worst defense in the league can't get much worse. At least they'll score more.
I'm sure it'll be rough seas for a few years, but they're still babies. I wouldn't give up hope right away.
Isn't the goal to eventually win titles though?
You're not winning titles with two average interior defenders. Nerlens Noel is still a "baby" he's one of the best defensive players in the league already, Gobert in his 2nd year is the best defensive player in the league, dudes who are good defenders are known for it almost immediately.