Hello John–excellent question!
The multi-site license is perfect for a WordPress network installation but not so good as far as licensing for each individual site. In this case, I would suggest purchases two Agency-level licenses, which will cover you for up to 20 sites. If you plan on adding a couple more sites to your list, then I would suggest the Unlimited-level license because it winds up being cheaper in the long run.
Does this help answer your question? Please let me know. 🙂
Cheers!
Geoff