Question about Brennos' interview

[Arjos]

*Though I think it is interesting that the Spanish languages (Catalan, Galician etc.) are the ones that seem more likely to use germanus as opposed to frater so that there may, indeed, be a deeper South-West European root. But the proposed Irish-Celtic roots are very weak.

I'm in no way a linguist, but could Goths, Alans, Vandals and Suebians have something to do with it?