Billski is right: tail volume affects both stability and control. As for one compensating shorter arm with a larger vertical tail surface, yes, larger surface usually ends up being a heavier solution. But I would like to call attention to another aspect: dynamic stability. Yaw damping is proportional to arm^2, which means that, with a shorter arm and same volume, one has less dynamic stability. In other terms: the aircraft is more subject to dutch rolls and yaw oscillations, which makes flying more difficult, especially with turbulence and landing/takeoff with gusty winds.