Actually, after contacting a number of Sluyter descendants, I have discovered that most "say that's the way it was" because someone way back when made a mistake reading my ancestor, Dirk Woodcock's will.
My Dirck was born in 1737.He had a daughter Annatje, born about 1772.She married a much younger Jacob Sluyter about 1797.My Dirck mentioned his daughter Annatje Sluyter in his 1797 will (probated 1806). (I have documentation for this.)
Unfortunately, many descendants of the older Sluyter couple have used the will to "prove" that the older Annatje Woodcock's father was named "Dirk." This mistaken genealogy got into the LDS records and is now posted all over the web.
I am not a Sluyter descendant, so I don't have a personal stake in who the older Annatje Woodcock's parents were, but if this is your family, you should probably take a look at the daughter of John Woodcock and Rachel Keyser.She was the sister of my Dirk.
If your Annatje was my Dirk's sister, the relationship would explain why my Dirk and his wife Elisabeth Decker were sponsors for the baptism of your Annatje's duaghter Elisabeth Sluyter, 1 November 1789 in the Reformed Dutch Church, Kinderhook, New York. Parents Jacob Sluyter and Annatje Woodcock, sponsors: Dirick Woodcock and Elisabeth Decker. ("Baptism Record of Kinderhook Reformed Church," transcribed and indexed by Arthur C.M. Kelly, Rhinebeck, N.Y. Kinship. 1985.)