In my VV2 games, I have noticed that the foundations of the 2nd hut appear when "we make" the 13th villager and the foundations of the 3rd hut appear when "we make" the 30th 31th villager.
You mean that we can't have more than 10 villages if the 1st hut is not finish (and 17 if the 2nd one s not finish) ?
In fact, I didn't notice that because my huts are finish quickly (they gain building skills!!)