From the Enemy's Eyes-Rohirrim Charge on Helm's Deep/Pellenor

[WarBringer]

yes, but the catapults do not need to be aimed, as you wouldnt be aiming at a specific target, both rather a mass of horseman. And trust me, as one who has studied such matter extensively, it doesnt take many catapults firing once to cause a whole lot of damage on pretty much anything they aim at.