Also, to me there's very little of "Nordicist" thinking IA Southern French or IA North Italians that might have been Celts or proto-Celts. The image of tall prehistoric barbarians coming from icy steppes sweeping across Europe with their chariots, like the Yamnaya, fits the bill way more - speaking of Nordicist imagery - than people whose phenotype had to be quite similar to their non-Gallic neighbours.
Now, thinking of Germanics or the British Celts would be another story of course.
As for the Nordicism prevalent in the forums, there are also those who think that the ancient Greeks were all tall, blond, and came from the Baltic Sea. Just to give an example. Of course, no importance should be given to this kind of Nordicism.
As for northern Italy, to be clear no archaeologist claims that all of Iron Age northern Italy was Celtic or proto-Celtic, and that it was aligned with Iron Age France. I am going by memory, while there are archeologists like Cavazzutti who supports that around 1700-1500 B.C. some areas of northern-eastern Italy, mainly the terramaricola area of Emilia and the castellieri of Friuli, have parallels in the Carpathian-Danubian plains of modern-day Hungary, as South-eastern Lombardy (Mantua) have parallels with the Gáta-Wieselburg of Eastern Austria and Western Hungary (areas that later in the Iron Age would be inhabited mainly by Etruscans and Veneti), and there are probably other examples here that I don't remember now, other archaeologists argue that northwestern Italy (Piedmont, Liguria, western Lombardy) is characterized instead by other archaeological horizons, and this coincides with the area of greatest Celtic influence in northern Italy: the Golasecca culture and the areas inhabited by the ancient Ligurians. Moreover, in a portion of this area since the 6th century B.C., the Lepontic language has been attested, which is considered the oldest attested Celtic language, and about which there are two hypotheses: a distinct Continental Celtic language or a language part of the Gallic subgroup. As far as I know, today consensus among scholars is still that Lepontic is a distinct Continental Celtic language, and that the inscriptions in Gallic are the more recent ones.
The Celts were in the Iron Age, the population covering the largest amount of territory in Western and Central Europe, and so it is fair to ask: from a biological point of view, were they all the same? Are there any genetic differences, for example, between the Alpine Celts and the Celts of the British Isles? To define someone a Celt had to belong to a well-defined genetic profile? When you talk to archaeologists and anthropologists they say that the biological aspect is just one of many along with the cultural, linguistic, archaeological aspects.
To date we have no archaeogenetics data on Iron Age populations in northwestern Italy. We can only speculate on the basis of the modern population, but these are conjectures, not objective data. Some archaeologists consider the term Ligurians in ancient sources a kind of broad term like so many others in ancient sources (Tyrrhenians, Pelasgians...). Possible that the ancient Ligurians were the oldest stratum in northwestern Italy, and that northwestern Italy received migrations of peoples we can call proto-Celtic. What genetic profile could those who wrote in the Lepontic language in the Iron Age have had? Here again we can only speculate. The chances are that they had, somewhat as in the case of Celto-Iberians, a genetic profile more typical of southwestern Europe rather than of central Europe (and somewhat like the Etruscans), perhaps with a significant number of outliers with greater Steppe percentages (somewhat like the outliers considered Celtic found among the Etruscans).
So, could they have been considered Celtic even if it had a more southern European genetic profile? I don't have any answer here, but if some scholar, with arguments that I find credible, considered them as such, a kind of Southern European expression of the Celtic world, I would have no problem accepting it. Also because ancient history is certainly not the ethnic estimates of some genetic calculator, and I continue to be more interested in ancient history over modern identity issues based on DNA testing. Besides, many modern ethnic groups have a genetic cline, not only the Italians, but also the Germans, the Greeks themselves and so on, yet no one would dream of claiming that they do not belong to the same ethnic group because of a genetic variability in the population.
To me it looks like the question of Indo-European origin has been largely politicized, i see different waves and it is quite problematic whom to believe.
This is quite evident, the question of Indo-European origin arose in the 1800s on obviously nationalistic grounds, and in fact among modern Indo-European linguists you still find some who suffer from this approach. In Germany you still find in some university departments of linguistics the label "Indo-Germanistics" (Indogermanistik), which is just laughable in my opinion.
I think this is an important point.
However the low WHG in modern Northern Italy (even more further south) compared to any part of France cannot be ignored.
Undeniable this. But this, however, remains an important point if you are interested more in modern over the Iron Age populations.
