thats why you rub your tobacco as small as you can in smoking contests
I have to (pardon the pun)
contest your supposition.
I'm not saying that it is incorrect, but there are other schools of thought in the slow smoke realm.
Small can be perfectly satisfactory, but from my own experience, a consistent tobacco preparation, that incorporates tobacco broken into small pieces that are not miniscule or "as small as you can" will burn at a lower temperature and for longer periods. For me anyway... larger spacing between pieces of tobacco allow for slower and lower burn durations and temperatures. The miniscule pieces will tend to clump and increase the size and temperature of the ember. This (IMHO) through greater contact between the bits of tobacco encourage faster ignition from one piece to the next. Where a larger (not big) pieces have fewer points of contact from bit to bit and that will retard ignition of the adjacent pieces of tobacco, resulting in a longer and much cooler smoke.
The various shapes of the cut are important as well. Larger pieces should go in the bottom of the bowl, decreasing in size as one nears the top of your 3 grams... Any powder-ish tobacco bits should be on top to facilitate a good char-light, which will facilitate a good-solid, and low temperature true-light.
Of course that is just my opinion, based on practice, experimentation, conversation, and practical application.
Sorry for going so far afield from the topic.