The longer answer: Even if you learned all 5 books, you’ll still need to study N5 and N4 grammar. JFZ Books we’re not designed to help you pass the JLPT tests, so they don’t cover everything found on the JLPT exams. That said, I think the JFZ Books are an excellent way to get started in that journey.
I’m only asking because your question stems from chapter 11 of course 1, which just covers the most basic things. So, if you’re learning new grammar in the first 2 books then you’re not level N5. Like I mentioned, knowing everything in the first two books is not enough to pass the JLPT N5 test, which also includes the most basic kanji (which are not taught until book 3).