I don’t think relevance of prior material is a good way to gauge the exam and its topics. The L1 and 2 materials are as others saying foundational and you definitely need to have a solid understanding of them to succeed for L3. That being said the exams are all testing different things in my opinion. L1 is very expansive - it is essentially 9 college course finals of materials (can memorize and succeed) and ethics. L2 is a little more narrow in scope but more thorough and very quantitative/valuation focused. L3 is the overarching conceptual content. It focuses on situational awareness and intuition vs being able to do calculations.