I was amazed that all the laws in Deuteronomy, Leviticus, and Numbers were actually pretty good laws for people living in a semi-arid ecosystem.

Exactly! The same here — it’s a perfect set of guides to keep the population healthy in that region in that time (plus the legal laws certainly helped to keep the intra-tribal strife to minimum).

plus the 11th

You mean “Love one another”? If yes, I would say it’s just a restatement of “Love your neighbor as yourself”, which is a summary of commandments 6–10 (with “Love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength” being a summary of the first five commandments). So, it’s still ten ;) But yes, they not only lead to a better life, they also contain a basic road map to enlightenment (which is however, for all practical purposes, saying the same thing).