Even I get confused when it comes to all the different options available with Microsoft cloud services.Some of my global customers have engaged with business analyst to perform the task of user profiling to try and establish what licenses end user really need per division.
One of my customers refused to buy AD premium for all users because they could lock down access by IP-range with ADFS and don’t need to license 23k users for AD premium. This is a very valid use case when you do the numbers and saves a lot of money.
Some of my customers want conditional access but do not have a compatible version of Office or OS and when the cost associated with bringing the desktop to a suitable level for conditional access for 10, 20k user sites, they are most often binned.
For global roll outs of Office365 , I aways recommend the use of a business analyst for user profiling to get the best value for your client or customer.
Microsoft always get their money!!!