The Explosive Crossbow has a very far range and has high damage, it is capable of taking on several enemies at once. For it to be in its most effective state you would have to use leather bolts and some sort of torch to light the bolts on fire. Once the bolts are lit on fire you should fire at the enemy. Shoot mostly below the foot to catch them on fire or the grass around them. Then you have defeated them and can move on.