Back before I did my Office 365 MCSA, I used to wonder which of the two exams would be harder - 70-346 (Office 365 Identities & Requirements) or 70-347 (Enabling Office 365 Services). Most people I talked to said they thought 346 was the harder of the two - mainly because they had far less experience with, and exposure to, ADFS and Powershell. Most took 346 after 347 and some didn't take 346 at all. That's a real shame. I took 346 first and would always recommended others to do so. Not because it was harder (it was significantly more focused than 347 in terms of scope) but because I feel that Identity really is the starting point for everything else. As an admin, how and what and where users can access services is as fundamental as it gets.