I just rolled a 1,1,1 stat in embarkation screen.
So I checked the files and at the Ascendancy population the minimal value for all stats are set as one, while in the Rayya the mind stat minimum value is 2.
I remember the plan was that each faction would have a little variation to its stats, and so far it was like this:
Ascendancy always have at least 2 spirit
Rayya always have at least 2 mind
North Alliance always have at least 2 body