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.
Discuss.
I think it was also suggested that the bow could be used to get a bonus, somehow, but at risk of breaking said bow... I think there's something to that, but Whilhelm would never have sacrificed his bow. 
I don't think anyone would, except in desperation. I've done medieval-style archery in the SCA (target only, no combat archery), and bows just aren't designed to be used in melee. Some of the others (knife and throwing axe) have melee equivalents that I can see using brawl (for knife) or Single Weapon (for throwing axe) to defend with. But if you've got a score of 2 in Single Weapon (Axe) and 9 in Thrown Weapon (Axe), I think you should use the 2 to Defend instead of 9.