Hi
Dafydd ab Owain - chart of his descendants looks like great confusion and no reliable sources. But this line (incl. John Owen) has many descendants, so I'm little confused also.
1) Cadwaladr ab Owain Cadwaladr ab Owain - married Margaret Pigot. No such person in Bartrum on Pigot charts.
Cadwaladr ab Owain ap Dafydd represented only on Gwyn ap Gruffudd 2 chart (https://www.geni.com/documents/view?doc_id=6000000173393063840), but no childs with names (Cadwaladr ap Cadwaladr; Margaret Owen and Owain Owen) shown.
2) Owain ap Cadwaladr married Margred Hanmer and his son John I Owen married Margred Hanmer also. But not such Margred, married to that people, on Bartrum charts of Hanmer family
3) David Lloyd Owen shown as married Alice Blount Owen (Oxenbridge). But I don't find such person nor on Blount, nether Oxenbridge trees. But there are profile Anne Blount , that married to Thomas Oxenbridge and David Owen.
4) Edward Owen shown married to Sarah Oteley. But at Visition of Shropshire (https://archive.org/details/TheVisitationOfShropshireV.29/page/n113...) Sarah Oteley married Edward Owen of Albrightlee, who shown with different ancestry. No son Richard of Edward Owen and Sarah Oteley.
+ https://archive.org/details/archaeologicaljo52brit/page/84/mode/2up also shown Owens of Albrightlee (that comes from Pontesbury family), who no son Richard
5) Richard Owen who was husband of Johanna Pitt, shown with many children, came to America.
But here https://www.wikitree.com/wiki/Owen-1466 and here https://www.wikitree.com/wiki/Owen-124 he is shown as no having children.
So John Owen - is may by needed to be removed from his "parents". at least. And other profiles mentioned - need to be corrected, deleted, etc
Bartrum conflated several men named Gwyn ap Gruffudd and we have not gotten around to sorting those charts out, yet. But even so, there is no guarantee that the line you are dealing with even comes from those charts.
The Cadwaladr in that chart did not marry Margaret Pigot, he married Margred ferch Dafydd ap Rhys Ddu, found in Cydifor ap Dinawal 8: https://www.geni.com/documents/view?doc_id=6000000173378451895.
Absent ANY sources it is not possible to see where these people belong.