I am curious as to the source of your information.
The parents of Wul(f)grim (d.886) are not known, but hypotheses abound. I
have not encountered the claim that he was a Rorgonid. Hence my interest as
to your source.
A plausible hyopthesis is that W is identical with Wulfgrim the known
brother of Adalhard (thought to be the father of Adelheid wife of Louis the
Stammerer and Charles III), Wulhard, Ymo and Hildeburga. Wulfhard and
Susanna were the parents of these siblings. Susanna is thought to be a
daughter of count Bego (d.816) of Paris by his (2nd?) wife Alpais (d.>852)
daughter or paternal half-sister of Louis the Pious.
While the hypothesis about W's origins is plausible, there are difficulties
with it. Much depends on what weight one places on features of Ademar's very
shaky account of the C9th families he discusses and in particular his claims
that (a) Wulfgrim was a brother of Hilduin abbot of St Denis and (b) a
relative of Charles the Bald. Ademar (writing in C11th) was not trying to
deceive but had little skill or feel for the sources he was using (and we do
know he used some good primary material no longer extant). I wont go on
about this hypothesis or Ademar as it takes us well away from your question
I suspect.
The name of Wulfgrim's wife is not known. Ademar of Chabannes says that she
was the sister of William of Toulouse (Willelmus tolosanus). Leon Levillain
seeks to identify Ademar's William of Toulouse with William (d.850) the
known son of Berhard (d.844) the marchio of Septimania and his wife Dhuoda
(most writers seem to accept this identification). Some authorities (e.g.
Europaeische Stammtafeln III/4:731, 817) call Wulfgrim's wife 'Regelinde'
but this is a mistake. Regelinde was the wife of William a son of Wulfgrim.
Richard
(rather less than 1000 kms from Perth)