Banega was great for Valencia, and was imo second best only to Villa there in terms of performances this season. But Cambiasso is an amazing DM, no way does he not deserve a starting spot at the NT.
He had a poor first few months, then got a long injury but then after that he started playing at his best, and indeed you're right, he had a monster season. Was easily one of the best players in the Ligue. I would actually go as far as saying he was the best in the second half of the season.
Lucho plays better as a central midfielder than behind the strikers imo. Thats the position he plays in for Marseille, as they too deploy a 3 man midfield.
Masch, Cambiasso and Lucho would have been perfect