I have a great tactic for the bigger clubs. I'm AC Milan and won the treble i my third season and I have not lost in over 40 games approaching the end of the fouth season.
I selected a 4-2-4 att from the tactics list and changed it to a 4-4-2 with the same team instructions. Against the bigger teams I lower the defensive line and sometimes I move the defensive CM down to a DM as well. Focus your passing to down both flanks. I have only conceeded 6 goals in 28 mathces and scored around 50 goals.
This is my starting formation:
GK - Ustari
LB - Veloso
CB - Fazio
CB - Machluof (unreal payer)/Zapata
RB - Abbas (unreal player)/Zapata
LM - Ronaldo/Cristian Rodriguez - depends on how tired they are
CM - Pjanic/Flamini - This is the more offensive CM
CM - Flamini/Camacho - This is the more defensive CM
RM - Messi/Ronaldo - depends on how tired they are
ST - Agüero
ST - Pato
If you're wondering where Kaka is, then the answer is Chelsea. I needed some changes and I rather sell him in FM than watching him in a Man City shirt in real life!!!
Tell me if the tactic is working for you guys