Ada de Huntingdon - The Peerage (online) lacking notes on Brereton family pre 15th century

The Peerage is not a reliable source, period.

i don't have the euros to access this anyway.

On Google books you can get Plantagenet Ancestry, which I find well sourced and fairly reliable.

I do not accept The Peerage as a primary source. There are a lot of such online resources that are filled with errors. Sometimes they are all that is available, but that means that there are no documents because if there were, there would be other more reliable and scholarly sources.

Yes, " fairly" is a good description. Because even this tome has its issues. I'm happy if I can take someone and get 5 citations from the likes of Orderic Vitalis, William of Jumieges, Wace, Watson, attendees at war, endorsement of dated legal documents, etc. And then compare who has what axe to grind in any given political/ power situation. And of course remnants of heraldry, the universal language of a time of illiteracy, fractured Latin, Norman French and Old English.