The players themselves have to be capable of playing this way. I don't think you can teach an established pro to suddenly become ball playing centre-half, and that is why many of them look uncomfortable. It's probably a better idea if you can coach the players while they are still learning the game. Leipzig have got a cracking young French lad who is only 20, and it's only a matter of time before he joins one of the big European clubs.
Incidentally, I think this may be one of the reasons why Ampadu hasn't played for them yet. He is clearly a very gifted ball playing defensive minded player, but he hasn't got the required passing speed or the intensity to slot into the team. This is not his fault as its down to coaching he received at Chelsea, but Nagelsmann has identified a few issues and said he will give the player some time to adapt. It should turn out to be a great loan move him, which will benefit Wales and Chelsea in the future.