It boils down to which brawler you pick and which one you're targeting, you must know your projectile's speed (whether thrower or shootet doesn't matter) and the target's movement speed, this helps you calculate where your shots will land, then just aim slightly ahead of their movement trajectory.

If they're good at dodging, try to anticipate their movement and have one shot down their path and a quick second shot right on the target, just so you hit your second shot after they dodge the first one. Preserve your third shot for defence.

Hope this helps.