As for scale armor only being used in the East, that's not true at all! At least by the time of the Roman Empire. Troops of the Roman Empire, especially eastern auxiliaries, would have been accustomed to using scale (
lorica squamata and the fancier
lorica plumata for officers) and bringing it to or even making it in Western Europe on occasion. In fact, we have archaeological finds of Roman scale armor from England, Wales, and Austria! Read this:
https://www.larp.com/legioxx/squamata.html
Mind you, none of these examples are Iberian or from pre-Roman Iberian groups, but they are still from Western Europe.