It's disingenuous to compare him to KDB, he's not that type of player. He's more like a Kroos/Yaya hybrid. Can stay deep and dictate play but also play that box-to-box role very well; as attested by his England performances.
I've read for Dortmund he's good as an attacking midfielder but goes missing when played deeper?
I was comparing him to KDB in that he was German player of the year before we got him.