Kurt, you seem to be visualizing Am. suburbs with a house and 4 family members in. Such house- even today- rarely exists in other countries. Even rich people have extra inhabitants: maids, cooks, gardeners etc. So 15 in the house is not impossible and no need for tents. Tents were used by Turks (originally nomads ), not the native Croats. Zagreb had a nice wall and the key to the doors was kept by families on a rotating basis.