It seems David and Daniel has been confused by transcribers. In the 1850 census only David was listed, in 1860 it was Daniel, different wife but same children. It appears Daniel remained in TN while David came to IL with his father.
Residences & events:
9/24/1850 Greesy Creek Twp, Coles Co, IL. The census recorded both David and Hannah at 27 years of age with 2 sons, James A, 4, and Thomas, 2. Also living there was David's 62 year old father Adam. The township was full of Collins relatives.
1860 Georgetown, Vermilion Co, IL. At census time he was 38 years old and a farmer but had only personal property valued at $250. Wife Elizabeth was 29. Children living there were James, 14, Thomas, 9, and Daniel, 2. Living with them was Daniel's father at age 70.