The Battle Of Jihan Castle [1]
"We won't be able to destroy the walls or gates anyway, so focus on building them quickly and striking them safely."
They decided to make a catapult that wasn't too big, and the stone it would throw wasn't too big either. The goal was to make it as quickly as possible and make Jihan's soldiers cower.
"But just in case, wouldn't it be better to make at least one big one? It might be able to break down the gate?"
"That makes sense."
Being a noble does not mean that one judges everything coolly and rationally. Sometimes, you might just want to give it a hot whack...
So, they built four catapults with low destructive power but long range, and one catapult with enough firepower to destroy the gates, if not the walls.