He had 21 goals in all competitions 3 years ago, I think Ralph Rangnick struggled with getting the best out of him for the year he was there, so he got 19 goals before Nagelsmann maximized his skills a lot better in the final season (34 in all comps).
I don't like talking abut isolated cases, as my point is more general. Bundasliga is a lot more open with higher lines, Shalke have conceded 80 goals in one campaign over there
. It's a lot easier to boost stats, and that's not to say players should be ignored but just to take their domestic stats with a pinch of salt. Sancho will come in and do very well wherever he goes, but I'd be surprised if he manages similar numbers straight away.