It wouldnt really matter abt a small difference. I remember seeing a twin engine light weight car with sequential gear boxes. The guy just flicked a small lever to move up a gear, and then another to change the other gear box up. He didnt even need to take his foot off the pedal. He could change gears in both at the same time. However, if he didnt, the engines could be running 1000s of rpms of a difference