Yeah, since PFs and Cs do most of the rebounding, they should be taller guys. Of course, there's no strength rating in BB. In real life, all your guys can benefit from being strong, while there are drawbacks to being too tall (too hard to handle the ball well, for example).
But yeah, the other response is important to look at, too, because a 6'6" guy with great rebounding, inside shot, inside defense, and shot blocking should be chosen over a 7'3" guy who isn't good at those things...but the 7'3" guy will train them faster, too.