Yeah I hear what youre saying. Generally you will be better off playing let them play, because even if he does foul out, 40 minutes and a foul out is better than 24 minutes and no foul out. Also I find that the aggressive players stay aggressive when you play sit them. So it generally results in two quick fouls, sitting for a quarter, two more quick fouls, and sitting for another quarter. Where as an aggressive player in let them play will pick up a few, but they will back off when they get into foul trouble. If they do foul out, its rarely in under 40 or so minutes.