The ammount of bbies means, the more bbies is the beter rating. The bbies ammount stacs cumulative but only if sizes are diffrent - same big bbies everytwhere dont stack and they half overall effect. So in conclusion as long as you keep enough ammount of diffrent bbies rating, the beter will be the picture - of course.
P.S. Enough of bbies doeasnt exist. Or maybe exist, its about 'string' or 'float'.