Ferreolus of Rodez - Wikipedia
Ansbert - Wikipedia
Arnoald - Wikipedia
Arnulf of Metz - Wikipedia
Ansegisel - Wikipedia
Pepin of Herstal - Wikipedia
Charles Martel - Wikipedia
It seems that it is indeed possible for the Carolingians/Pepinids to rule either WRE or the Goths due to their pedigree, how would have they rule the Goths.