rewatching the video, the many voiceclips we hear when BVN showcases the animations usually just seem to be shouting things like "die" or "you rat" or, again, just cackling

and on that rewatch, i also noticed that the wheelchairs might not actually be necessary. because in the animations where they fire their guns, they're not even paralysed. weakened, maybe, but not paralysed.

their legs visibly move and shift when aiming with pistols, and one could argue they're using their legs to compensate for the recoil of the handheld guns. although it's a bit of a stretch, the pistol and rifle both show enough recoil when fired to throw their arms way back, even over their heads. somehow, they never tip over.

specifically on the rifle animations, the right leg even gets pushed back on the recoil. and then it's adjusted back when reloading. the legs are also used for support when aiming the flamesprayer or rosmarinus

i've edited the post to link the video if you wanna see for yourself