[sionnsar]

There’s another reason the counterweight is hinged...this helps to better transfer the potential energy in the weight to the kinetic energy of the projectile.

Need to stop and consider this because it's not intuitive. Given that the change in elevation of the counterweight is significantly less with a hinged weight, there's less potential energy to transfer.

[rottndog]

Given that the change in elevation of the counterweight is significantly less with a hinged weight, there's less potential energy to transfer.

This is simply augmented by adding more weight. They tried one trebuchet with solid lead ingots around the end of the swing arm, and actual tests showed the hinged bucket resulted in longer shots with the projectile.