Looking through the rules for Star Wars: Edge of the Empire role-playing game, I noticed that thrown weapons such as grenades and nets are agility based being Ranged (Light). I was wondering why it isn't Brawn (hurling a rock is a fairly brawny task i would think) and if it would be acceptable to treat impact driven thrown weapons as Brawn (probably Brawl) and keep the rest of the thrown weapons (such as grenades) as Ranged (Light)?
If the fight was about who could throw the rock the farthest, sure. But it is about hitting someone in the face, and therefore it is more about your accuracy than how hard you tossed the rock.
What the test is modelling is your character's ability to hit the enemy and the damage variability is the difference between hitting them in the chest and hitting them in the head.
Fundamentally, hitting the target is about accuracy. Accuracy is axiomatically Agility.
The role of brawn in thrown weapons is in the base damage for impact-based damage thrown weapons. Several thrown weapons use the "+X" damage notation, which means "Brawn + X", while explosion based damages are all listed as "X".
Also, given the abstraction of range bands, the range bands are too wide for brawn to make a difference in overall range, unlike how a more grid-based combat system might adjust grenade ranges by the brawn of the thrower.