Rover tuning parameters

I am trying to tune the steering on my rover but have not had success. I have followed the “Tuning steering and navigation for a Rover” with limited improvement. Here is a clip of what it looks like in action
It is a skid steering using APM , Sabertooth 2x12 on a Wild Thumper 4wd.
I’m not sure what to try differently or do I need to go back and try again?