Walter FitzAlan, 1st High Steward of Scotland - Inconsistencies

This interests me because both are in my direct (great grandfather) family line. A search of Wikipedia on 'Walter' perhaps might shed more light OR be the source of conflict. I'll let you decide. Here's a link: Walter Stewart, 3rd High Steward of Scotland - Wikipedia
en.wikipedia.org/wiki/Walter_Stewart,_3rd_High_Steward_of_Scotland

Walter Stewart, 3rd High Steward of Scotland. Jump to navigation Jump to search. Walter Steward of Dundonald (died 1246) was 3rd hereditary High Steward of Scotland and Justiciar of Scotia. He was the eldest son of Alan fitz Walter, 2nd High Steward of Scotland but which wife of Alan's was his mother is not clear.
Geneaqlogy shows short history of Simon: Simon FitzAlan, 'Buithe' d. Yes, date unknown ...
geneagraphie.com/getperson.php?personID=I23428

Simon FitzAlan, 'Buithe'. However, he was also described as Simon of Norfolk in a confirmation of a joint grant by his parents Alan son of Flaald and Avelina de Hesdin perhaps before he came to Scotland. There does not seem to be any record of his wife.