Even though my son Izhak held with learning in depth, still he recognized the importance of Rav Nahman who strongly held with  the approach of fast learning ["just say the words in order and go further" אין צריכים בלימוד רק לומר הדברים כסדר וממילא יבין    ם "In learning one only needs to ay the words in order and then he will automatically understand and if he does not understand right away, he will eventually understand; and if after all of that, there are still left some things he did not understand, so what? For the greatness of a lot of learning goes above everything else." so one needs a balance, deep learning in the morning and fast learning in the afternoon. This is the compromise that most Litvak yeshivot have arrived at after a few hundred years of experience.