Jack, I, too, believed that the MD DishAroon family was a different family than my DishEroon family. They may be, but everything that I have found puts William with the Waitman who came from MD. I will send you all the notes that I have on William the father of Seaborn. There is very little information on William, son of William because he died so young.
I really believe that the Capt. William you refer to is the father of Waitman. That William has a brother named John who lived in MD. I found no mention of a John in NC.
Also, some of the descendants of William spell their name with an "A" and some just "Dishroon".