The first generation in America should be David Allen, Sr., b.c. 1714 and d.c. 1786. This David had two sons. The first is the Adoniram you have listed as being born in New England circa 1734 and d. in 1838 in Clay Co., Ky. This is Capt. Adoniram Allen. He fought in the Rev. War along with his brother, David Allen, Sr., b.c.1761 In New Jersey and d. 1842 in Alabama.
Aley was not born in Scotland. From the 1850 Clay Co. KY, Census, Family 547 David Robertson, farmer, age 70, b. in North Carolina and Alie Robertson, age 60 b. in North Carolina with Columbus 20. So Aley was born in probably Wilkes Co., N.C.
If you get a chance please send me how you descend.