The output speed of 600rpm is very high for direct driving the robot.
If you have external gear ratio reducing motor output to wheel speed 3:1 then wheels will get 200rpm, which is the same if you had used 200rpm green cartridges to direct drive the robot.
When programming autonomous it is always better to drive at reduced speed for higher accuracy.
Many use algorithms where you first gradually increase velocity, then drive most of the way at 40-60% of top speed, and then gradually reduce speed at the end of your route.
If you are ready to learn more advanced programming you may study “motion profiling”.
These topics have useful examples and links to OkapiLib and other programming resources: