Father of John, Joseph, Nicholas, and Thomas Holt

What was the relationship between John and Joseph Holt who married sisters Helena Maria and Edith White? Three Louisa County deeds help to steer us to the answer. The three deeds include: July 8, 1758 Louisa County VA DB B page 333-334 Joseph Holt of New Kent County and Joseph Holt Jr. of Louisa County VA ..."give a negro girl named Fanny and all her increase"...witnessed by John Holt and Elisha White (The witnesses to this deed tell us that the Joseph Holt we've been following in Louisa County is also known as Joseph Holt Jr. The question is, who was Joseph Holt of New Kent County?) September 25, 1759 Louisa County VA DB B page 333-334 Joseph Holt Sr. of New Kent County and Nicholas Holt of Charles City Co ., "for love and affection... 400 acres in Louisa County on both sides of Treasurer’s Run" (Joseph Holt Sr. appears to be the same Joseph Holt of New Kent County in the previous deed. But who was Nicholas Holt?) March 26, 1762 Louisa County VA DB C ...