It's extremely unlikely that anyone was born in Ohio in 1740. Nelson County, Virginia, likewise did not exist; both places were pretty far west of the colonial frontier at the time. It is also unlikely, although possible, that someone born in 1740 would have a middle name (they didn't become common until the early 1800s).
Are there any primary sources for this John Wade?
On edit: where are the primary sources for his marriage to "Mary Sarah Harnden"? She's on the FamilySearch tree, claimed to've been born in Massachusetts, which seems very unlikely if this John Wade was from Virginia and died in Kentucky. A quick Google Books search shows results from the New England Genealogical & Historic Register that list a number of Wade/Harnden marriages in Medford, MA; is seems like this John Wade may have been conflated with an entirely different person.