It is not sure who the parents of this profile, or his siblings, are. If he is the son of Abjörn, then the LNAB should simply be Abjörnsson.
This profile has been disconnected as son of Abjörn Sixtensson. Sources suggest that Abjörn and his wife only had two sons, Ulf and Nils. No sources provided to imply this profile belong to the house Sparre af Tofta and therefore the LNAB should not represent that.
Online trees suggest there was someone named Abjörn Ulfsson, "Sparre från Västbo", example https://www.geni.com/people/Abj%C3%B6rn-Ulfsson-Sparre-fr%C3%A5n-V%C3%A4stbo/6000000018448056480 Could possibly be connected with Jon Kristinesson? https://sv.wikipedia.org/wiki/Jon_Kristinesson
As suggested above, they are most likely children of another Abjörn or they can very well be fabrications or "internet lore" in order to connect family to nobility. WikiTree should not replicate mistakes made at other genealogy sites, only if somewhat reliable sources for these profiles can prove they might belong in this family they should be reconnected. TL request has been send March 1, 2022 in order to edit LNAB. Andersson-4409 12:25, 1 March 2022 (UTC)
See also;
A > Abjornsson Spare av Tofta | A > Abjörnsson > Laurents (Abjornsson Spare av Tofta) Abjörnsson
Categories: Sweden, Pre-1500 Needs Work | Sweden, Needs LNAB Changed | Unsourced Profiles | Sweden, Unsourced Profiles | Uncertain Family | Uncertain Existence | Sweden, Uncertain Existence