Inter Milan growth depends on the manager, and how he relates with the squad, I see every player looking for a team with more game time so they can have a spot in them National squad ahead of the FIFA World Cup to be held November/ December.
Asides Lukaku, they have Dybala, Larturo Martinez who are good players, they also have a great vision for goal, it will be a long season, the Champions League will be a great one with new players representing then new club's.
Lukaku is going through a really bad form right now. He has not done anything worth mentioning in the English Premier League. I believe that he is just not made for the English Premier League. He has done well in other leagues. So, I think it will be better for him if he plays for any team except in the English Premier League. Dybala also could not show a good performance in the last season because he was injured a lot of times. I think a move for him is also going to do great for his career in the future.