Something has come up in one of my other sagas that has made me consider a House Rule for this one.
To wit: Defense scores when you're using a ranged weapon. Under the 5th Edition rules, if you're using a bow, for example, you get to add your Bow Ability score to your defense. If it's like, say, a 10, then you get to add a 10 to your Defense if you're using a bow. Which is like, huh? How...what...facepalm
So...proposed House Rule (which is basically going back to the 4th Edition combat rules): If you're using a Missile Weapon (p. 177), you only use your Brawling to defend.