Javelin throwing units

[Lormax]

Whats the best way to use these things? I've played Vanheim a few times, and the javelin guys have me very confused. In my mind, they sound great...wait until the enemy moves close enough, fire javelins then charge in...in practice, they stood there and took the charge. Whats the best set of commands to have them stand and wait, fire when the closest enemy reaches their range, then attack? Thank you