Strafing vehicles... I think I like that idea. Come to think of it, the ability to dodge really does seem to be something that is missing from the OP combat system.
Granted it would be virtually useless for panthers and tigers, but it might be good to give some of the smaller vehicles the ability to reduce the enemy's accuracy by staying in motion.
Really you wouldn't even need a ball drive, since the vehicles have turrets anyway, they could drive on their normal wheels while spinning the turrets to stay in contact with the target.
I wonder how much of an advantage moving while attacking would actually confer on an OP vehicle... Would enemy turrets still be able to track it more or less as effectively as before, or would there be some loss of accuracy?
For the ball drive specifically, I would personally worry about how much dust and dirt would get sucked into it. Would you be able to keep one clean enough not to get jammed in the middle of battle?