Has anyone mentioned the animation bug yet? If an archer or crossbowman is killed by a sync animation (whether by sword, spear or polearm) while they were still holding their bow or crossbow, they'll perform a strange seizure animation before morphing into a t-posing dwarf with their legs planted into the ground.
It also appears to be directly related to a blinding visual bug that occurs when fighting swordsmen in particular in a walled settlement (I found the visual effect far more extreme using Venetian Colonial Archers (shown below) than Arsenalotti Crossbowmen).
Interestingly, in my experiments I (accidentally) found that certain units such as the Magyar Foot Archers and Hungarian Crossbowmen are not affected by this bug.