On all compound bows the cables take up most of the load once the limb have been flexed to the drawn position. The poundage of the bow and let-off are the determining factors. The limb configuration is of little consequence other than providing a stable capture to the riser (We had a Legacy that the limbs wanted to walk back out of). The single cable on a 1-cam bow is really "strained" (as you put it) because there is only one and the entire load on the string is let-off, while this same load is distributed through 2 cable on a dually.