Nagelsmann is of course a very good coach but he's at an early stage in his career. Klopp for example had years to test, fail and fine tune his style of play. Tuchel is a similar case. Even Guardiola to a lesser extent.
As impressive as his career is up until now, it's essentially his first year of coaching a top club and he'll probably find out that not everything that worked at Hoffenheim or even Leipzig applies to the new situation because in the end, teams still play differently when facing Bayern than they did when facing Leipzig. He has to adapt to this new reality and that's not a given (albeit probable, unfortunately
).
I still think it's premature to name him in the same breath as Guardiola, Klopp and Tuchel. Ten Hag is a better comparison. However, I do think that his approach is much better suited to a top team than Nagelsmann's which lacks control at this point in time. You can't just steamroll teams all the time.