Well, Sartar was always travelling, even when he was king. For exemple : "Sartar was loved by the common tribes people, for he often went disguised among them and searched for those worthy and just enough to help convey the kingdom towards a good future" (Composite History of Dragon Pass, The Kingdom of Sartar, in King of Sartar)
We know why, now
About round houses... There is a kind of stone round huts of old that were used by the shepereds :
You don't find them only in France, but also in Spain, Italie too, and i'm quite sure you can find them on other countries. Most of them are built in the exact same way the stone "beehive" huts of Bronze Age Ireland were built. When I imagine a young heortling sheperd and his alynx inside, I can't help to think to young Orlanth and Yinkin in Kero Fin cave ^^ In my Glorantha, there are the typical shelters for Sartar's sheperds home away because they have lead their flocks of sheeps to the "summer" pastures