We still haven't decided what board to use or where to place the witch. How about starting position below (mentioned previously but not sure if you agree).
I like your witch idea and her moving ability. She is very agile! (Moves like Q + N + jumps orthogonally and diagonally 2 squares). So I gave her a broom.
The diagram below is an example of the moving ability of the witch (green is white witch, blue is black witch) just to make sure we understand the same.
Is all this OK?
The third would make a great witch, I'm ready if you are.