What exactly is the usage case here though? You already get "unlimited" quotas, so combining them will not yield anything. On the other side of the spectrum, if you want to restrict the quota for a given user, you can easily do so via the admin tools.
I think he's talking about the home office 365 accounts that come with 5 licenses. Those are not unlimited like the enterprise sku's.
On that note thou, you should be able to setup 5 users and then Share the OneDrive with your primary user and be able to sync the locations locally to have the storage space to use, not ideal but it would work.