Rav Nahman of Breslov and Uman actually has two places in the LeM where he seems to contradict himself. In one place he says to learn "Poskim" [the medieval authorities that wrote on law. This is different than medieval authorities that wrote commentaries.] separates the good from evil--since that is the whole purpose of the poskim --to come to clarification of the law. [However I should add that in the terminology of Rav Nahman, the word "poskim" means basically the actual Shulchan Aruch of Rav Joseph Karo (who was not a Rishon). He was the beginning of the period of the Achronim. However, it is clear throughout his writings that "poskim" to Rav Nahman means especially the actual Shulchan Aruch with its commentaries , the Shach, Taz, Magen Avraham, etc. 

But in Le.M vol. I, chapter 54, he says the "כוח הדמיון שורה על שונה הלכות" ["Delusions rest upon those that learn halacha."] And there is no mistaking his intension there as he goes into great detail explaining this.

But I think that a simple answer is that he uses the word "shone halachot" שונה הלכות not "lomed halachot." לומד הלכות [To be "Shone" is  meant to to say the words and go on. The word "lomed" means to learn in depth.

So the best idea in terms of Halacha according to this would be not to be "shone halachot",  but rather to learn in depth starting from the Gemara and going through the Rosh, Rif, Tur, Shulchan Aruch with the basic commentaries on the Shuclan Aruch. [Later note, actually I think the best of all halacha books, the Tur with the Beit Yoseph is the best.] 

Incidentally, this is how I was taught in my second year in Shar Yashuv (the yeshiva of Rav Friefeld). Only in the third year there did they start with deep "lumdus" [learning] as you can see examples in Rav Shach and Rav Chaim of Brisk.

[There is a way of learning in depth which is to review the paragraph 10 times, and  that helps me to learn Physics and Math.]