Everyone has their (different) take on players. For myself, Ninis is nowhere near the level of Mantalos or Fortounis.
The cruciate ligament injury he had in hist last season at PAO in 11/12 just took something from the kid. He's never been the same. He went to Italy (which is a good thing) in 12/13 and played with Parma largely with stints off the bench. Even though he didn't get the game time I'd hoped for, he was still at a good club in a much better league with better players, better facilities, better everything. He would learn what it means to play in a real league.
So when he came to PAOK in 13/14 I thought, "here we go, Ninis is going to tear up the Greek league". I couldn't have been more wrong. He was virtually non existent for PAOK. Same again for PAO the following season.
He's only really started playing decent since moving to Charleroi. And he's still not in the first 11 most weeks. Usually gets subbed on or off. I'm not sure if this is a fitness issue or what is going on. Regardless, I think it's too early to be talking about having Ninis in the NT.