Some of Edward’s descendents claim he arrived in NC with the Kennedy and Henderson families in 1728. It is not known where he came from, but he married a Sarah or Sabrah Jarrott before 1735 in NC. One of his known descendents is James Howard of Cumberland Co., NC, who married both Edna Banner and Honour Everitt. Obediah and Seth both have similar names in their ancestry; including Jarrett/Jared which makes me wonder if they may have been other sons of Edward. Only further research or DNA results can answer this question. 

One of the first places we find Seth Howard mentioned is in what became Craven/Jones County, NC where he was given a piece of property from Robert Orme, who appears to be related, but I have seen no confirmation of how. (There is an excellent book on this family: Howard-Wright and allied families: Bates, Burch, Childers, Clardy, Collins, Cox, ... by Marilee Howard Cory) 

 Obediah is first found in Orange County, NC and  was/is thought to have been a brother of Nehemiah Howard also of North Carolina.  There are two prominent theories about Nehemiah, one that he is descended from  the line of Edmund Howard of Somerset and Charles Counties, Maryland; the other
  that he was a son of Stephen Howard who died in North Carolina in 1745 (?)  with two known sons who were mentioned  in the will of John Sanders in the 1730’s as cousins. These Howards were thought
to be descended from James of Nansemond County, VA. None of these Howards have  been connected yet through DNA testing (that I am aware of).

Obediah has been found to be closely related to Seth Howard of Craven/Jones Counties, NC and James Howard of Cumberland County, NC.