learning fast and also review and learning in depth. [

Even though Rav Nahman of Breslov emphasized learning fast there are also a few places where he does bring the idea of review and learning in depth. [Sefer Hamidot and LeM I:78] It does not seem that there is much of  question of which to emphasize since you can see in Conversations of Rav Nahman that the learning fast thing was his major emphasis. [section 76],

If you apply this to learning the natural sciences, Math, Physics, Chem, Biology, then the rule is clear. Learn fast with no review. Say the words in order from the beginning to end.

[Many Rishonim held from learning the natural sciences. That started from Rav Saadia Gaon and Ibn Pakuda.] 

So review is less well defined when and how to go about it.

I suggest in one of the regular sessions to have one session where review is done in the way of starting sta some middle point and working a few pages forward and also a few pages backwards.

[But one should avoid pseudo sciences and pseudo Torah. In fact outside of STEM, anything with the word "studies" attached to it is pseudo science. As for Torah, only the actual written and Oral Law are Torah. That is the actual Old Testament and the two Talmuds and midrashim. Everything else is false Torah or fake Torah.

natural science is pretty clear is most rishonim. However philosophy seems to be an area of contention. The Ramban [Moshe ben Nahman] did not like Aristotle at all. And that means all that followed his approach. But Ibn Pakuda [Obligations of the Hearts] differs as you can see on page one of his intro to his book.