You may not know but Kai Havertz was formerly playing as a 10 and play maker, he was then more or less transformed into a support striker but his biggest strength is his vision and passing ability and therefor is best when he has movement in front of him. The team would lose stability with a real 10 though, no matter who would play this position. I am with Tuchel, I don't believe that a bit more creativity would be worth the less stability.