This is a bit late but the story about JAMES Collin McKinney who died in Pulaski County, Kentucky in 1811 and who left a will naming his heirs is never found in any document using the given name James. He was just plain Collin McKinney.
So far as several of us can figure out it was an early McKinney researcher who tried to shoe-horn all McKinneys into the Mordecai group who needed to give Collin McKinney a new name. So apparently the James is a name that the poor man acquired in the 20th century . . . .
There is no record of James Collin McKinney or Collin McKinney having that first marriage. That was part of making the whole thing work. By giving Collin a first name they made two men into one man. Pretty nifty if you can do it.
So far as is know Collin McKinney of Pulaski County had only one wife and she was likely Rebecca Tuttle.