I agree 2 in the middle is a huge problem when you don't take advantage of your overload in the wide areas. I feel because we don't trust the wing backs we try and play through the middle, which limits the speed of our transition.Two in midfield is still a huge problem when playing out from the back. Passing options were easily shut down. Only changed in the second half when Fulham had to chase. They got ragged and we found it easier.
This is then doubles with Son being unable to hold up the ball.
However I am a believer we need to have the right personel to move between 2 and 3 in the middle of the park.