You can't get more waltnerdy that this - I'm a civvy asking a question about weapon physics! - but here goes. AFAIK, the justification for the wooden handle of the old German "potato masher" grenade is that it increased its thrown range, because the handle acted as an extension to the arm and therefore provided extra impulse/moment (turning force). The Germans persisted with it through two world wars. However, to my mind, the reasoning is faulty. The argument for extra range certainly works for the stone-age spear thrower, the sling, and the cesta (basket "glove") of pelota, but only because the payloads (spear, shot, and ball, respectively) are separate from the throwing tool -- the arm's "extension" -- which launches it. However, the stick grenade's handle is of course part of the grenade, and so it seems to me that any extra impulse it provides simply goes into making the thrown grenade rotate more rather than increasing its range from the thrower. Besides, if range is measurably impoved by adding a handle, why not just add the grenade to the end of a pole throw it even further?! You may be losing the will to live at this point.