You can, and there are pro's and con's. You get more surface area which in return allows for more application of rub and creates more bark on the meat. The downer is that it may cook too quickly and run over your desired finished temp before you catch it in time. Also, if it is a lesser, less tender cut, it may cook too quickly to gain the benefits of low and slow cooking. One thing which is debatable, is that with smaller pieces you have more surface area for smoke to collect, but in faster cooking, you essentially offset the increased potential for smoke reaction with the meat by reducing the time it has in the smoke.
For more tender cuts of meat which do not really benefit from low & slow cooking which you would not take to high finished temperatures, the smaller pieces cooking faster would do no harm, provided you didn't overshoot finished temp, of course. Here again though, is that you reduce the time for smoke reaction, thereby reducing smoke flavor.
Say you get small cuts in the smoker, run it at ~225* for30 minutes to pasteurize the surface, then turn the heat down to 200 to slow it down for more smoke reaction...I've done that, and it does help the smoke flavor. Smoking very cold meats also helps, as it takes a bit longer to reach finished temp from 35* then from a tempered meat that reached room temp (I don't temper my meats...cold storage to smoke).
Eric
