There are no classes with such heavy weighting on primary stat that it behooves them to use A variant mods. The closest you get is Trooper/BHs which have a 9% to primary stat, but, even then, the loss of so much secondary stat isn't worth it.
So, the Aim weighting for a Dread Guard geared gunnery commando is nearly double the weighting of Power. Crit is the only secondary stat which comes close, and even then it's quite a ways behind Aim. Obviously, the 9% boost is factoring in here, but that alone isn't enough to account for the kind of disparity I see in the numbers. In other words, I'm not entirely sure *why* Power is weighted so low (comparatively), but it is.
None of the other classes I've ever looked at show that kind of balance though. Usually, power is on par, if not superior to, main stat.