If Bernardo stays another top mid like Kimmich would be too much to share minutes. Kovacic arrived for Gundo. Adding Kimmich won't work with Phillips supposed to take more minutes too.
Forget about Kimmich as RB, he's a mid now and that's what he wants.
But beside his strengths as a player, he isn't an easy character! He is extremely overambitious and the opposite of Gundo's charming and diplomatic personality for example. He's a hothead and a littler stinker if things go wrong. Jack woulld have fun winding him up all day long ;)
If you think Germans have no humour, Kimmich is the classic example.