While not suggesting that this is how compound bows work in Layo (since in Layo you actually make them with cams and whatnot), but late ancient and medieval compound bows did not have cams or cables. It was made by layering bone, wood, and sinew. Hence the name "compound." They were very effective, but took a strong fellow to use. Unstrung, the bows literally bent backwards on themselves. Early "catapults" and "ballistae" were based on his technology, essentially being gigantic compound bows. It wasn't until a long time later that iron replaced the compound bow as the better material for superior torque, and thus we have crossbows. Unfortunatley for crossbows and bows in general, advances in gunpowder made guns far more cost efficient to use for armies.
Err... okay, that was slightly off topic.
