Couldn't they have fixed the issue along time ago by making ballista and catapults etc. not able to hit people? I mean come on, really, what is the likely hood that a ballista would hit a single person 300 feet away and further. The person only needs to take a step to the left or right to dodge it. It should also take the ballista time to load.

Instead they start modifying range and what not. Sorry but that's kind of stupid.

Just make the ballista take down the wall bonus and keep the range even.

To keep the catapults useful allow it to knock out traps and abatis as it rolls.

Voilą.

I'm a Genius.