We had the same young players playing last season and Fernandes playing higher has nothing to do with them, that's a very special stretch to put it on the young offensive players. The reality is that your point made no sense Ole changed a system that he has used for almot two seasons to accomodate the certain players, if we follow your logic these players should have adapted their game and Ole shouldn't have changed the system.
The way you put one would think that the only difference between last season and this one is that Ronaldo and Varane have been added to the starting eleven. Today Ole effectively adapted his 2 years old system to accomodate mainly Ronaldo and allow him to start next to Cavani instead of playing wide, he then added a CB in order to free the fullback since he decided to get rid of one of the wide players in order to accomodate Ronaldo.
In other words Ole adapted the system to the players that he wanted to start, these players didn't adapt to the system Ole originally used. That's a fact and not really debateable.