What do you think of this map Miri?
My point was that both Strabo and Romans(how they organized Aquitania) distinguished peoples like Tarbelli, Sotiates, Elusates (who later will get their "Novempopulonia" province) from Celts living in Burdigala(Bituriges). Since we're at breaking CA vanilla cultures, splitting for example "Celtic" in numerous subgroups, we have to do the same with Iberic peoples.
This being, I wanted to propose an Aquitanian subcultural group(and put Vascones and Tarbelli, Elusates...etc together).
If you look closely how Romans separated Bituriges from Aquitanians, and creating different Cohors for them, its clear to me all these guys didn't wanted to be mixed in the same province nor in the same military units. Thats why you have Cohors Aquitanorum Biturigum(composed of Celts celts celts, the Burdigala guys) and Cohors Aquitanorum(composed of Aquitanian, proto-basque, closer to Vascones living in actual Spain).
Miri, just to precise, in case you may suspect something, I'm not Basque
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If you look the shape of roman province "Aquitania Novempopulona"(no more Bituriges into, Novempopulonia means "Land of The Nine Peoples", and are considered proto-Aquitanians), you can see shape of the province and linguistic distribution are almost conflated, that match almost perfectly)