I agree with what both of you are saying but maybe Oscar is not being lined up for the #10 role...
Have a look at these excellent articles written on Oscar-
Article 1 and
Article 2
Their is a strong argument to be made that Oscar can make the transition from a #10 to a regista role....
He is two-footed meaning he can pass with both feet. Excellent Composure. He can pass while on the run. He is adept at playing diagonals, through balls and lofted balls from deep positions. Interesting point to note is that he usually drops deep from his #10 role anyways to play a part in the build-up. He plays with his head up and has excellent balance
Not to mention he is very versatile. He can play anywhere in the band of 3 behind the striker as well. Also very young at 20 and at a club that are willing to sell.
Many people believe he can make the transition to a 'regista'. He has the technique, work-rate, passing and composure to do it. Maybe he was even being brought to Spurs as a replacement for Luka Modric? It would certainly make sense as Spurs just bought Gylfi and has not yet sold Van Der Vaart.
Also Oscar can say what he likes about staying... One of his agents Carlos Meinberg said
'"Chelsea did offer €25 million, but there is still no agreement between the clubs, that may happen in the next few days,"
His main agent Giuliano Bertolucci is also Ramires and David Luiz's agent.
I like Oscar a lot. For 25m Euro's we can not only shore up depth in the attacking positions but also get a regista at around half the price for Modric. Obviously Oscar will have to make the transition but I think he can do it.
Sorry mate but your wrong here. Marin/De Bruyne are more of conventional wingers while Oscar is a #10 who can play on the wings if needed