At the time of this writing, we have Richard de Roet as the son of Paon de Roet, who died before he was born.
So that's not good.
but wait! There's more!
Because Payn de Roet was the father of Katherine Swynford, who would go on to marry John of Gaunt and be the ancestress of a whole lot of people, including royals, AND the father of Philippa, who would go on to marry Chaucer, and be the subject of a lot of discussion amongst English professors, we have a LOT of research on the family.
and there is no Richard in there. Katherine and Philippa had a sister named Isabelle/Elizabeth, and a brother named Walter, but no brother named Richard that we know of.
But this connection is floating around the internet on family web trees. Lots.
Where it comes from is from building the Rowett line on up. Various sites tell us that the Rowett name has been in England since the Conquest, though I haven't seen anything that builds a genealogy from it. And various sites also say that Roet and Rowett are alternate spellings of the same name (along with Rawett and some other variants).
And here is an old angelfire site which gives a pedigree of the Rowetts, connecting Richard to Payn de Roet, entirely on speculation, and giving no evidence whatsoever: http://www.angelfire.com/my/cornishroots/page53.html An earlier page in the document says that the Rowett family is allowed the three Catherine wheels of the original de Roet arms, so that there is a connection is a reasonable conclusion. But no clear line of connection.
So. In summation.
Richard Rowett (not de Roet) is attested, in Northampton, by land documents, and his children show up in wills and land documents -- I've got no reason to think he didn't exist.
Payn de Roet may or may not be connected to him; if so, we do not know how.
I propose disconnecting Richard de Roet from Payn de Roet, who could not have been his father; changing Richard's name to Rowett, since that's how it appears in the records, and adding in notes explaining the situation, and a link to the de Roet family.
The families may very well be connected. But I'm not seeing any evidence as to how.
If anyone DOES know of primary evidence connecting the two families, please give it!