No Knowledge Amongst Military and Diplomats of Siege Machines...?

When the Chinese bring the mobile tower on rails close to the walls, all military and diplomats are wondering "What is that?" Unbelievable. When most of them are highly read military or learned men. Remember the British Ambassador, the part played by Niven had a set of French history. And the French Ambassador had a set of British history!

That tower is a siege machine used by all nations to bring castle walls down. Even Romans! There were some with ramps and ladders that were dropped over the castle walls so infantry could jump over. Others with different weapons. The Chinese are shown firing rockets.

Should have been known by at least the Europeans.