"Celt" Conjecture

[Conal]

Strabo is saying Greeks met Celts on the southern coasts of France which in ancient times was inhabited also by Ligures. Strabo also points out that Ligures and Celts have similar ways of life.
But you should note there's little known about ancient Ligures and many speculations were made about their language: that it was another Celtic language, another IE language or even a non-IE language.

So, any notion that the original "Celtic" language being Ligurian based on what Strabo says is bit of a stretch.