The SHRM certification exams are not easy, as most people who start investigating HR certifications soon find out. Both the SHRM-CP and SHRM-SCP exams are fair, but tough, and each covers a lot of ground.
Early-career HR professionals likely need to study all the HR knowledge areas and competencies when preparing to take either level of exam. But even mid-career and senior HR professionals who have greater knowledge and more experience can be weaker or stronger in some knowledge areas or competencies versus others.