Pixhawk V8 Configuration

I have a Sky Hero Spyder, with 8 motors in a V configuration (short forward arms and long rearward arms to give a better view for the camera) and a Pixhawk.

Currently I am flying it with the Pixhwak configured as a X8 copter. I notice when yawing that the copter wobbles quite viciously. Should I reconfigure the Pixhawk for a V configuration? If I do, what should the wiring order of the bottom motors be?

@Hans2004,
How about providing either tlogs and/or data flash logs to help troubleshoot your issue?
Regards,
TCIII GM

I will make a sensible dataflash log as soon as the weather allows. For now I really would like to know so much if it is possible to configure the pixhawk in a V configuration with four arms, but with 8 motors (in a pancake configuration) and what the motor order would be. The rear arms are nearly twice as long as the forward facing arms. When I yaw slowly, the copter stays perfectly level. But during fast yaws it wobbles strongly around the pitch and roll axis. I read somewhere that in a V4 configuration this effect shows when the pixhawk is actually configured as a X4. But I cannot find a V8 configuration setup in mission planner.