https://en.wikipedia.org/wiki/John_Sedgwick

I would like to see a video of a trebuchet. Modern or not.

The probability regimes in which science is dealing often only leave marginal room for alternative explanations.

As in, the grave itself was dated, and 5 of the 9 skeletons found inside were also individually dated to roughly the same century. Maybe the other 4 were not tested, or turned out to have been buried at a later date.

Can we? That Wikipedia page is inconclusive, and thus article says:

During Edward I’s 1304 siege of the castle, English forces deployed the recently invented trebuchet, a weapon first documented in the 12th century. A cousin to the catapult, trebuchets were capable of hurling boulders weighing more than 100 kilograms hundreds of meters. One at Stirling, dubbed “War Wolf,” “was the biggest trebuchet ever built at that point,” Buckberry says. Eyewitness accounts confirm the giant siege engine was used during the 1304 battle, tearing through two stone walls “as an arrow would fly through a piece of cloth.”

Accounts of the battle don’t mention any trebuchet casualties. But Buckberry says Skeleton 150’s injuries strongly suggest at least one defender was hit from behind by a flying boulder, launched by War Wolf or one of the other siege engines arrayed outside Stirling Castle’s walls. “It’s a huge amount of energy delivered in milliseconds,” Waltenberger says. “In skeletons from past times you rarely see this.”

from the article: “skull broken in 61 places”

Doubt you’d stay conscious long enough to notice

From 1935. And he was not the first one to point that out either.

I actually think that thanks to the internet, we expose many more criminal build ups towards warfare nowadays than before.