I liked the way Kentucky was handled in Frank Hunter's ACW game.
1. Kentucky starts with no forces of either side present. As soon as one side sends in troops, it takes offence and aligns itself with the other side. No random element. This is what happened in reality, as I understand it.
2. Both sides can recruit troops from Kentucky regardless of who 'owns' the state. This also happened in reality.
There were simply more Unionits than secessionists in Kentucky and Missouri than there were Secessionists. Lincoln was originally from Kentucky. East Tennesse and other fairly large areas of the South were pro-Union, as evidenced by West Virginia seceding from Virginia. The same in most civil wars, and the English Civil Wars are a good example of divided loyalties within local regions and even within counties themselves.
Both sides did recruit in the Border States and certain areas of the South, and the majority of the people in these areas were pro-Union and supplied many more troops and gave much more support to the Union than the Confederacy. Therefore, IMHO, I believe that the majority of people in these States and regions knew that they would inevitably side with the Union if civil war did break out, and that is what happened.
Chris
'What is more amazing, is that amongst all those approaching enemies there is not one named Gisgo.' Hannibal Barcid (or Barca) to Gisgo, a Greek staff officer, Cannae.
That's the CSS North Carolina BB-55
Boris Badanov, looking for Natasha Goodenov