Del is absolutely right, but it's also about arrow weight. War bow shooters are launching heavy arrows, sometimes up to 1/4#. With these massive arrows, you need as much working limb as possible to optimise cast. It's like throwing a shot put, as compared to a baseball. Non-bendy handled Victorian style ELBs generally throw light weight, target style arrows, like a player throwing a baseball, mostly with the wrist and arm, while full compass war bows throwing heavy arrows need to use their whole body to move the heavy shot.