What we see in the archaeology is the appearance of Etruscan settlements where Villanovan settlements once stood. Why? Perhaps they co-existed and eventually merged into one culture. The Romans called these people Tusci or Etrusci, creating the link to the region later called Tuscany.
The Etruscans were farmers first – taming the wild land of Tuscany to grow emmer (a type of wheat) which was husked and unsuitable for bread making until they were able to create new cultivars. Olive oil was unknown in Etruria as late as 581 B.C, but must have been imported from Greece. Home grown wine grapes, like olive trees came later. The Etruscans were skilled at irrigation, and the excavated tunnels suggest an organized approach and central authority behind the engineering.