I disagree, although I agree with your larger point about Leipzig.
Hummels is a little out of form in recent weeks, so he's getting criticism for that, but he was Dortmund's best player the first few months of the season. Also, Favre has just started letting Zagadou play again. He's been brilliant, and the defense has specifically played much better since he came into the lineup. He was the one, not Akanji, that unfortunately lost his starting spot when Hummels came in. They don't make a good pairing because they are both 6'5, so we have to play 3 at the back and add Akanji, whose incredibly shaky. So our CB position is very average with that back 3, but I don't agree that Dortmund doesn't have good CB's. The good ones just don't pair well together.
PSG is trotting out guys like Diallo, Kehrer, Kimpembe, all worse players than Hummels and Zagadou. Thiago Silva is getting up there in age. They don't even use their best CB, Marquinhos, at CB anymore.