Yes it certainly sounds like there is a connection to your Clarence Horatio somehow. The Clarence I mentioned who was son of Robert & Cordelia had a brother Alberto b. 1849 and sister Marie b. 1860.
The father Robert Nero had one only brother Horatio but he died in Chicago, IL (Nov. 1862)while serving in the Civil War at 21. His only child, Lucretia,was b. 3 weeks after his death.
The only other male I know of was Horatio Fulton, UNCLE of Robert Nero. I have no dates on this Horatio but he was said by a contemporary to have "left town under less than favorable circumstances." I have found nothing further on him. His siblings were Robert Nero's father Robert Jefferson Fulton (known as Jeff). They also had a sister who left the family with their mother - the name of neither woman has been determined at this point.