Catapults versus Trebuchets

[Ildar]

I saw an onager in a late medieval technical treatise

Stefan, the illustrations from Kriegsbücher don't support the existence of the onager in the Middle Ages, as I already wrote in my paper, because "apart from illustrations in some Late Medieval engineering treatises, a vast array of other illuminated manuscripts does not have any illustrations of one-armed torsion engines, whereas the illustrations of traction and counterweight trebuchets, crossbows, bombards etc. abound."
These illustrations go back to two or three prototypes only, so there is strong probability that they could be redrawn from the same now lost ancient treatise. Besides, many of these illustrations have details, which were well known in antiquity, but were hardly possible in the Late Middle Ages.