Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Each customer would have their own volume license.
I've given up on installing or managing the OEM/Retail version of MS Office for my clients. I try to steer them towards either O365 or volume licensing (VLS). While VLS has a large up front cost, don't forget, it's a perpetual license and offers a lower TCO over time vs. O365, assuming there isn't a need to upgrade to the next version (or even two) of Office. Most of my clients abhor the thought of a never-ending subscription to MS Office and so far have opted to avoid it at all costs. If my clients still want the OEM/Retail edition, I'll continue to sell it to them, but I won't attempt to activate or manage their licenses for them.
As I stated earlier in this thread, along with many others - I really don't think MS cares about the current activation hassles. The subscription model is where everything is headed and I seriously believe this (Office 2016) is the last time we'll see an OEM/Retail edition. They've gotten a taste for the recurring revenue O365 provides and they're hungry for more. Even Windows has already headed down the subscription path... Watch for the whole industry try to mirror the mobile ecosystem. The app store will be front and center with free versions available, but the features you really need or want will require a subscription.