I cant really evaluate Granero good, b/c i havent seen him playing that much.
Now Sahin had a certainly good season - but his first really good season in his career. His main contribution comes from his playmaking as basically, he is doing in Dortmund what Xavi does for Barca, Xabi for RM, Schweinsteiger does for Bayern and the german NT etc. On top of that he adapted nicely to Klopps hard pressing game. And that could maybe set him over Xabi, b/c he is more mobile and pacy than him and better at "active" defending. Maybe thats what Mourinho is looking for ... but i dont know ...
On the other hand, like i mentioned above, he has a much much lower reputation and lobby at RM than he has in Dortmund. And every playmaker and focal point of the team needs to have that - otherwise he just wouldnt get the amount of ball contacts a playmaker needs and usually has. And that could be the key obstacle that makes him fail. B/c i just cant see Xabi to sit down on the bench, taking it "professional". And the other players also wouldnt respect him from day 1 and use him as first passing option.
And he has a very similar situation with the turkish NT, where he is sth like an "outsider" and thus couldnt seettle yet - for seemingly the same reason.
Well, i just evaluated his decision for career-related criterias, not for emotional ones. But when we are talking about "home country", you should know that he was born in germany, lived his whole life in german, knows Turkey from vacations only and i doubt he speaks the turkish language that fluently, but most likely worse than german ...
And thats why joining the turkish NT is so bad imo, not (only) b/c the german NT is much more successful: he would have had it much easier to settle into the german team, as he is known there and respected among the BL players, has several team buddies from Dortmund in the NT and is adapted to language and mentality - much more than in Turkey. For the other turkish players he could easily be some outsider, trying to take over the "real turks" spots. And that makes it much harder imo.
