Genealogy is all based on the dubious assumption that over hundreds of years not one of the wives “jumped the fence.”
Statistically speaking, that is highly unlikely.
Wives were a lot truer than most think. I noticed a while back that several members of my Mothers Clan had some kind of DNA tests done which trace ancestry back through the male lineage only.
I remember thinking that if any of the Fathers were not really the Father then the tests would not agree with the genealogical data. It turned out that they all were related exactly how they thought they were.