Let me put it in perspective
If you got 10 worldclass players, but play without a goalkeeper, a decent goalkeeper is an insane upgrade.
ergo
If you have amazing talent in midfield, but the lack of an aggressive physical player really hurts their creativity and actions, adding this player is a massive upgrade.
Its hard to understand, but this isnt FIFA17, where Pjanic, Gotze, Isco is a legit central midfield