Agree with you. Caesar, it seems, inflated a bit the number of "his" vanquished people; and Sardinia, a stone surrounded by sea, has never been the land for huge demographic colonization, as its today population seem still showing; so, crossings, mixing, but not at a high scale.
Celts in Eastern Andalusia? I dont think so. THis region had surely a denser pop than a lot of other regions of Spain, with long tradition of evolved cultures, among them CHA and BA El Argar I suppose come from East Mediterranea and not Steppes via North.
apart and answering other posts:
Mozarab is a linguistic term (not the best it's true) and was a latin dialect of central and southern Iberia under Muslims controle; it had some intermediary Ibero-latin traits but for I know had not the peculiarities shared by Galician and Portuguese; it conserved the initial F- as other Iberian dialects at the exception of Castillan (H-) but it is not a typical trait - I can go deeper in details if someone wants but it is not the very thread and others can surely do the same as me. Today Andaluse seems a Castillan dialect spoken by different people, with very different phonetic habits -
For Urnfields, I don't know for Spain but in other parts of Western Europe it has implied pops moves and increase in demic densities, with some anthropologic traces from Northern-Central Europe in France Rhône region by example. Only Celts, not sure, I don't know. We can suppose they were Celtic speaking in Iberia, at least the elites, spite we can also suppose other Celts were arrived in Northern Spain already before them. Maybe a wave of archaic Celtic speakers, like in Ireland? Unsteady ground without proof.
According to some scholars, Iberic language would have had some Basque- or Aquitan-like loanwords as well as some Celtic loanwords.For me it could have been absent at first in Andalusia/Murcia... ATW a not negligeable number of words seem of a common origin in Basque and Iberic and general phonetical tendancies link both, with a slight opposition to Aquitanian; I wonder if the Iberic basis would not have been a far cousin of Aquitano-Basque or "Gasco-Aquitanian", with modern Basque being a Gasco-Aquitanian imported more recently into South the Pyrenees, and submitted there to common phonetic habits proper to some ancient Iberia folks and a bit different from the North Pyrenees habits?
I would be glad to can date the first apparition of the lineages of DF27 in Iberia; when and where?