I was watching a video of a storm attempt on the in game version of Athens and it occurred to me that the breach (besides being comically oversized compared to the ballistae projectiles, as if they were throwing gunpowder explosives) is that the breach just seems impractically large for the amount of effort it would take to achieve it. On those rare occasions that besiegers would attempt to knock down the walls, did they attempt to make breaches that wide? What means did they use to achieve these breaches? Are there any notably effective/massive breaches in ancient warfare?
Although Romans had access to larger siege weapons, even the largest were throwing stones less than 30kg, probably less than 10kg! For formidable fortifications, this would generally have little impact unless a weak portion of the wall could be targeted. The biggest problem with projectile based siege weapons is that they make it incredibly obvious as to where a besieging army was going to attempt to breach the walls, giving ample time for defenders to reinforce and even repair said wall against further attack. Generally, the plan for ancient armies was simply to bypass the walls if possible by building up earthen works or through siege towers.
If an attacking army really wanted to take down the walls, the most effective way to do so was undermining, which could result in fairly spectacular collapses of relatively large portions of a wall. Of course defenders would be looking for this; it just was less obvious than a catapult tossing a small boulder every few minutes at the same section of wall.