So when I said viking kingdoms, I meant areas where vikings (or similarly naval raiders/settlers) could come from, not kingdoms they established.
Ohhh I misunderstood the original thread -
Ok well the Scotti according to this Wikipedia entry and I have read this many times before in other sources says;
"Charles Oman derived it from Gaelic Scuit, meaning someone cut-off. He believed it referred to bands of outcast Gaelic raiders, suggesting that the Scots were to the Gaels what the Vikings were to the Norse". https://en.wikipedia.org/wiki/Scoti
Interesting however that many societies/cultures now considered defined by their current location were originally identified as either sea raiders or "land raiders" or an invasive force that had no definitive home to call their own.