I believe that I can connect your Stancill,Battle,Mayo line into our Williams line, and to the Battle line,at least tentatively.
Elizabeth Mayo who married Nathan Stancill was the sister of Lucinda Atkinson May (Mayo). Lucinda married Issac Battle on 23 Mar 1803. I believe they only had one son, Joel Allen Battle.
Issac was the son of Charity Horn and Williams Battle, the parents were married1774. William, in turn, is the son of Henry Horn and Anne Purcell married 1737. The children from this marriage are the following:
Col William Horn who married Celia Richardson and then a second time married Mary Thomas, Esther Horn who married a Andrew Ross, Isaac Horn who married an Edith Richardson and Henry Horn II who married Sarah Battle. Continuing...Jacob Horn married an Elizabeth ?, Mourning Horn married a Wilson William Curll, Phebe Horn married a James Rick's, Joel Horn married a Sarah Ann Harris, Thomas Horn married a Celia Ann Vick, Charity Horn married a William Battle (which is where your Stancill connection comes in as his son was Issac who married Lucinda Atkinson Mayo, sister to Elizabeth Mayo Stancill),... continuing children of Col William Horn and Mary Thomas.... Celia Horn, andthen Demaris Horn and finally Jeremiah Horn who married a Pheriba Peele May (Mayo?????) This last another possible connection, perhaps another sister???
Obviously, there are a couple of connections here to the Battle family. Our Williams line connects through the daughter Milbrey or Milberry Horn who married Joseph D. Philips. She was a daughter of Col William Horn II who married twice: once to Celia Richardson and then again to Mary Thomas. She comes from the second marriage. Joseph Philips, Milbrey's husband, had a bunch of children and another daughter Margaret (Peggy) Thomas Philips married Josiah Frederick Williams who is a direct line for my husband's family line.
I am happy to share what I have, but would prefer to send the line via snail mail. In some cases I have proofs but not always, so the line might be incorrect but I believe it is mostly correct.
I would have to go backwards in my files to see if I have more on the Battle line, should you want more specifics on that particular line, but I believe that your Stancill line connects through the relationship of Elizabeth Stancills sister's marriage to Issac Battle, son of William Battle and Charity Horn.
By the way, Issac Battle who married Lucinda had two other siblings: Joel Battle who married Mary Palmer Johnston and Ann Battle who married Daniel Ross.
Other surnames that connect with this Horn line are the following:
Neal, Purcell, Richardson, Thomas, Philips, Wharton, Hewitt, Buchanan, Price, Harper, Davis, Peyton, Greene, Ellery, Williams, McIver, Hunter, Ramsey, Donelson, Bate, Love, Dismukes, Vaughn, Porter, Pennington, Flethcer, Rozell, Martin, Ramsey, Patterson, Edmundson, Dance, Seip, Brown, Flint, Tanner, Ewing, Hord, Wendell, Dunlop, Leavell, Coulter, Webster, Stewart, Bland, Cunningham, Finley, Elder, Cartwright, Heath, Dunn, Brennan, Day, Nicholas, Van Boddie, Sanford, Haskins, West, Baker, Blackwell, McKown, Donnell, Dryer, Whitaker, Gould, Holmes, Maston, Warner, Lindsley, Duncan, Black, Richardson, Sample, Burton, Duncan, Wade, Eldridge, Frizzell, Henderson, Terrace, Shwab or Shawak, Kennedy, Price, Smartt, Clark, Harding, Demoville, Dahlgren, Demonille, Thompson, Cozart, Finn, Dennedy, Polk, Moore, Bunn, Granberry, Norfleet, Fort, Suggs, Reade, Costafney, Ricks, Harris, Vick.