Not really. If in doubt, just get Herc weapon.
And, weaponS? Aside from Dartagnan's HP weapon, stay away from them. Just stick to the elemental Atk ones - they're just too damn good to pass up on. So if you feel like there's absolutely an element that you absolutely must have Andromeda for some reason, just get the offensive one. But chances are you'll need to farm the Herc weapon later.