Dorne is definitely influenced a bit by Spain, a bit by Wales. But nothing is one and one. I took that together. Dorne is a very special land, with a slightly different cultural basis than the rest of Westeros…it was politically apart for a long time, it was also culturally apart because of the Rhoynar and the traditions they brought, but they didn’t influence the rest of Westeros so much. So the dornish have their own particular sort of customs. I see that in Spain with the whole history, particularly the Moorish history of Spain, you know…it really sets it apart from France.
In the case of Dorne, yes, Wales was definitely an influence, for all the reasons you cite. But there’s also some distinctly unWelsh elements down there. South of the wall of mountains [the Red Mountains] you have a hot, dry country more like Spain or Palestine than the cool green valleys of Wales, with most of the settlements along the seacoast and in few great river basins. And you also have the flavor given the culture by the great Rhoynar influx led by Nymeria. I suppose the closest real life equivalent to that would be the Moorish influence in parts of Spain. So you could say Dorne is Wales mixed with Spain and Palestine with some entirely imaginary influences mixed in. Or you could just say it’s Dorne