Yes its a quote from J. Lemprière (C. Anthon) 1833, based on M. Amedee Thierry hypothesies which is based on the account of Plutarchs writing concerning the battle of Aquae Sextiae.* (quoted below) and the Livius, statement "Insubres, pagus Æduorum". Far fetched logic, agree.
Umbrians as akin to the Celts/Gauls:
James C. Prichard - Ethnography of Europe: Vol.III (1841)
"Solinus informs us that Bocchus, a writer who has been several times cited by Pliny, reported the Umbri to have been descended from the ancient Gauls;
[Bocchus absolvit Gallorum veterum propaginem Umbros esse]
and a similar account of their origin has been adopted, either from the same or from different testimony, by Servius, Isidore, and other writers of a late period."
[Umbri, Italiae gens est, sed Gallorum veterum propago]
Isaac Taylor - The Origin of the Aryans (1890)
"Towards the close of the neolithic age the same Aryan-speaking race [Indo-Europeans] which constructed the Swiss pile dwellings seems to have crossed the Alps, erecting their pile dwellings in the Italian lakes and in the marshes of the valley of the Po. Helbig has proved that these people must be identified with those whom we call the Umbrians. This conclusion, established solely on archaeological grounds, is confirmed by the close connection between Celtic and Italic speech, and also by the almost identical civilization disclosed by the pile dwellings of Italy [North] and those of Switzerland."
Luke Owen Pike - The English and their Origin (1866)
"If now we consult the Umbrian language with a view of discovering whether it approaches more nearly the Gaelic or the Cymric type, we find, scanty though the evidence may be, that Umbrian differs from Latin in precisely the same manner in which Cymric and Greek differ from Latin. The Latin qu becomes, in Umbrian, as in Welsh and Greek, p: e.g. Latin quatuor, Umbrian petur, Welsh pedwar. The Welsh uch, uchel, appears as the Umbrian ucar, the Greek aixpog; the Welsh hwra as the Umbrian hri, the Greek aipsco;"
The "Gallic" Insubres were infact Umbrians (IsUMBRI-IsOMBRI)
Polybius called them Isombri [isOMBRI] and Strabo Symbri [sY(i)MBRI]
Matthias Koch - Die Alpen-Etrusker (1853)
"Auffallend bleibt jedoch immer, dass in dem Insubrer-Namen der Umbrer-Name steckt. Polybius, der Erste, welcher die Insubrer nennt, schreibt oi'Iσομβροι , und 'Oμροι und 'Oμßρixoi heissen bei den Griechen die Umbrer,"
The Umbro-Ligurian mix:
*Plutarch - Lives (120 AD)
"they [Ambrones] often called out their name Ambrones, either to encourage one another or to terrify the Romans by this announcement. The Ligurians, who were the first of the Italic people to go down to battle with them, hearing their shouts, and understanding what they said, responded by calling out their old national name, which was the same, for the Ligurians also call themselves Ambrones when they refer to their origin."
Whether the Ligurians were a pre-Indo-European or an Indo-European people is a grant debate. But Anthropological(Archaeological) skulls and bones identify the Ligures with the Pre & Non Indo-European Lapps.
Werner Sombert - Vom Menschen (1938)
"Die alpine oder ligurische Rasse: breitköpfig, dunkelhaarig, den Lappen und Finnen verwandt."
Roberto Bosi - The Lapps (1977)
"Then [Rudolf Karl] Virchow. examining a number of Lappish skulls at Helsinki, Lund and Copenhagen, in conjunction with ancient Ligurian skulls, discovered many mutual features suggesting an identical strain."
As for the Sicani:
James C. Prichard - Ethnography of Europe: Vol.III (1841)
"Thucydides commences his narrative of the war of the Athenians in Sicily with a particular account of that island, and of the races of people who inhabited it.....The Sicani appear to have been the next settlers.......they were Iberes or Iberians: having been expelled from the river Sicanus, in Iberia, by the Ligurians,"
Edwin Guest - Origines Celticae (1883)
"Emporion lay a little north of Barcelona, and in calling it the 'Liguan Emporion', Scylax agrees with Thucydides, who represents the Iberian Sicanoi as having been expelled by the Ligues (Ligures) from the Sikanos, i.e. from the basin of the Ebro.
Next to the Ligues, who dwelt in the neighbourhood of this river, came the mixed Iberes, who reached as far as the Rhone. Festus Avienus makes this river the dividing line between the Iberes and the Ligures, who inhabited the Alpine district.-"
So it is clear that everything East of the Rhone was Ligurian, everything West of the Rhone was Iberes (mixed; poss. with Ligures / poss. with Celts), and South of the Pyrenees was Iberes except for a region on the Ebro that was Ligues (Ligures) after the conquest and expulsion of the Sicanoi (Sicani).