Large Rover having trouble in Acro/Steering

The beast just starts going in circles or a motor shuts off. All kinds of bad. I have throttle learning finished but the steering is just a mess.

2 Sabertooth 60’s and 4 wheelchair motors.

LOGS: https://www.dropbox.com/sh/g1ddth3o48u310m/AAAxJiH-KzH554whV3hxjX6ta?dl=0