I can't really say where and how to cut. All the "saga"- relationships until (maybe) 900 are more or less fabricated. The fictional profiles in geni should be clearly labeled like "this person may never have existed and all relationships are ...." Find some good label.
After the labelling action - I don't think this would be an easy one - the worst parts of the sagas could be disconnected.
However - the pre-medivial geni-tree is not even a correct image of the sagas - it is not only Odd Örvar and his cohorts (hirds). Most of the saga trees seem to be a playground for fantastic queen-king-children stories.
The tales about Orvar and his "father" Grim are really unlikely (even if some persons and events might have existed/happened). I think that tales do not belong in a serious genealogic website.
I have compared with "wikitree". There are a lot of tales too. However they label the profiles:
https://www.wikitree.com/wiki/Dagsdotter-2
"Biography
This is a legendary or fictional person. Therefore she can not have parents, spouses or children and she can not have real dates or events. The parents previously linked to this profile, Frodosson-1 and Anfantsryrdottir-1 have therefore been disconnected as well as her husband Alfreksson-1, Agnisson-2, The_Powerful-1 and child Agnason-2, Alreksson-36, Alriksson-1.
Her profile is being retained on WikiTree because she appears in many popular genealogies.
From Heimskringla saga/legend:
Dagreith (Dageid in Swedish, Norwegian and Danish) is mentioned in the Heimskringa saga (in the Ynglingasaga part) as the daughter of king Dag the Powerful (Swedish: konung Dag den mäktige, Norwegian: kong Dag den megtuge, Danish: kong Dag den Mægtige).
She in turn is the mother of possibly both the sons of spouse Alrek (son of Agni/Agne), named Yngvi (Inge) and Alf (Alv), at least she is spoken of as the mother of Alf (Alv). [1] [2]
Relationships between historical figures could have been simplified or even fabricated in the text to give the impression that succession remained within the same family. Precise chronology is also difficult to assess from the Sagas. The conclusion must be that the tight family network described in the Sagas is unlikely to be correct and that the relationships should be treated with considerable caution."
When wikitree is presenting a very doubtful tree like they label the profile:
"Research suggests that this person may never have existed. See the text for details"
https://www.wikitree.com/wiki/Domarsson-5
(open "descendants" with three times "queen" Skjalv Frostisdotter; two times to much)
I guess that you know the labels of wikitree.
I was surprised when I noticed that Curators produce saga-profiles like the following and almost all the others in this tree surrounding without a note that "the profile might never have existed." I suggest that curators should agree upon "profile-rules"
Olvor, an Irish princess
The Irish princess has a name in the sagas: Olvor with two "," below the o's.
"Chapter 21-24 in Orvar's saga: They are traveling two times to Ireland. On the first trip Asmundr gets killed; on the second Oddr receives from the king's daughter Olvor a shirt in which he could not become injured. He marries her and stays in Ireland for three years."
Well the worst part is not that the fictional profiles are included in the geni-tree without label, the worst part is that the tree is suggesting that all these Orvars and Anunds together with all their wifes, brothers, children and kohorts are related and some users seem to believe that Anund or whoever is their 38th grandfather and maybe related to the pharaos.