Real Madrid tactic has nothing to do with how they play in real life.
Most of the time, they play 442 or 433 under Ancelotti. They exploit the middle, the most funny part is that they use wingbacks as wingers and Ronaldo plays as a striker most of the time. Under Ancelotti, it is just pure chaos. They used 4231 only several times. Isco does not play as T, he tracks back a lot and sometime switches from MC to left flank. They use wingbacks, not fullbacks.