Yes, I agree. I think there were factors, that were important for her defence, that she didn't want to use.I am no expert but I think it is the difference between lacking mental capacity and being mentally ill. I think you have to be capable of understanding right from wrong, but you can still be mentally ill and stand trial.
Again this is all my opinion but I imagine parting company with so many KC's may have been because she was refusing to follow some "obvious" plea path?