The main distribution on Italy peninsula ends about at the border of Lazio to Campania (Roccomonfonia [41]).
In the south (San Fili [42], Monte Oliveto [43], Monte Aspromonte [44] and Monte Gargano [45]) Podarcis muralis in a mountain species (see map).
This depends on the change from Podarcis s. campestris (campo = meadow) to the nominate race Podarcis s. siculus.
While P. s. campestris is more a "meadow species" and doesn´t climb very well, the nominate race is a very good rock climber, much larger and stronger than the Wall lizard and displaces P. muralis to higher elevations, where its to cool for Podarcis siculus.
- Distribution of Podarcis muralis on the Italian peninsula
So your thousands of lizards look so different is, because there the is the color/markings transition zone from campestris to siculus, although these are genetical true siculus.
Mario