I wouldn't trust the Lee of Nordley line as far as I could throw it. It comes from one of those books.
The Blounts claim descent from the Conqueror's admiral. They aren't the only ones - William must have had a bunch of admirals.
The Alfred claim is going to be about the ancestors of the alleged admiral. But it's probably true by accident, because valid Alfred lines were easy enough to marry.
The main Anglo-Saxon royal bloodline was taken to Scotland by St Margaret and then back to the English northern gentry by William the Lion's illegitimate daughter Isabel.
There's also a back-door route to Alfred through the Counts of Flanders. This is inherited by Henry I's numerous illegitimate kids and a bunch of other early Anglo-Norman barons.
WikiTree shows many more lines through Alfred's grandson Adalulf
https://www.wikitree.com/wiki/Boulogne-9
but MedLands doesn't join up the Counts of Boulogne.