My hypothesis:
I think R1b were nonconformist people whose were exploring to settle where they wish, always looking for a better way of life. Spreading from their original core in SW Iberia, and probably an important part of them were seduced by basque-aquitanian country way of life,country which in the surroundings were inhabited in those times by cromagnoids whose had speaks the language known as basque, So the R1b basques became sedentary with very attachment about their land, adopting a foreign language, the cromanoid language. R1b and cromagnoids were mixed forming the modern celtiberians (all around Iberia, not only in basque country). Another R1b people continued their voyage to French Brittany, Ireland, Scotland, Wales, England. Then became another expansion from the isles to Norway, and from Brittany-Aquitania to Central Europe. the R1b Central European people spreads to north Italy, the East Europe and Catalonia-Aragón-Rioja-Navarra in Iberia. The most plausible origin of R1b was in the SW of Iberia. At this point is very important to considerate the celtic "castros"(spanish word) in Cogotas I y II, and all about Vettons in general.