Two identical VFD breakers fed off identical conductors protected by a single breaker...? There shouldn't be an issue as long as conductors are sized appropriately with respect to the main breaker, correct?
................./------------breaker------------VFD------------motor
main breaker
.................\------------breaker------------VFD------------motor
................./------------breaker------------VFD------------motor
main breaker
.................\------------breaker------------VFD------------motor