This ancestral line is probably more myth than reality. There is no documentation that would support it. It seems to depend upon a speculative assumption that the father of Asle Dugalsson and Eirik Dugalsson (who was the father of Pål Eiriksson) is the same person as Dugal Ruaidhrisson, Lord of Kintyre and underking of the Hebrides (born before 1249 and died 1268). This connection has been taken very uncritically by lots of folks with Valdres ancestry. It is probably based on a suggestion by G. Munthe in "Samlinger til det norske folks sprog og historie". For more on this, see the article by Anders Stillof entitled "Omkring Store-Kvåle i Vestre Slidre: Sigvat Andersøns og ulvarna Jodgeirsdatters Efterslekt til 1600" in tidskrift for Valdres Historielag, vol. 12, pp. 65-92, 1934.