Currently:
If i am shooting someone with my bow and they engage me in melee combat. i can continue to aim and shoot at them. given that you can make bows that can kill in 2-3 hits even if they have good armour and the fact that the guy in melee must stand still. this makes melee skills almost useless. as a ranger with enough unarmed to hold off the first sting will win. if the person in melee attemps to dodge around you waiting for cooldown, you can simply punch him with no offence bar, completly draining his defence and giving you 1 advantage. and if you want, you can now beat him down with your fists instead of shooting him.
the normal "moves" a melee fighter will be performing is charge, jump and dash initially. all those moves "sound" like they would reduce a rangers aim. however they currently do not.
Suggestions:
1 .While in melee, any combat move you perform should heavily reduce aim or break it.
2. any reduction in aim causing aim to equal or go below 0, should break your aim. you should have to reaquire your target.
you may have to make an exception for call down the thunder, but i donno.
so basically if you sprint up to a ranger, and charge him, it should break his aim. if he wants to try and aim again and try and shoot you before you charge or dash, he can try, but that next charge or dash should also heavily reduce aim or break the lock. this would also affect shooting animals in melee, and generally make ranged combat more about killing from range, not in melee.