W.H.
My children are well past kindergarten, but both my children were at McFadden and I know a child who was in kindergarten at Discovery last year. Cason would not accept county school students so we were not eligible to go there. I think you should arrange to go to Cason Lane, McFadden, and Discovery and observe their kindergarten classes. Talk to the kindergarten teachers and ask your questions, no one knows your child the way you know your child.
You also need to be aware of the different calendars of these three schools. Some families want the year round calendar some don't, make sure they fit your family schedule.