I have been researching John Alexander's line.He was born in Burke Co, NC and came to Wayne Co, IN in the early 1800's.He was married to Ruth Penland. By 1832 he and his family had moved on to Cass Co, MI.I have more information on this line if you want it.One note of interest--an early census showed a James Alexander living next to John Alexander.So there may be an unknown connection.
The only connection that I have currently to your James is that a descendant of Margaret Ireland, Alpheus Ireland, married Sophia Alexander, the daughter of my John Alexander.The names of William and John appear so often in the family lines that it is difficult to sort them out.
You mention Wayne County, IN and Randolph County, IN as well as Preble County, OH.These are all neighboring counties on the Indiana and Ohio line and many of the friends, neighbors and relatives moved around in that area, but John and several of their friends moved on to Michigan about 1832.As far as I know none of John's children married in Indiana.
Sorry I can't be of more help to you.If you learn anything further please let me know.