pretty sure shooting a couchers shield makes them temporarily stop couching
It does for about half a second.
That being said, people are lucky that couching (or thrusting) lancers aren't holding the shield more directly in front of them. What's the point of having a shield if you're going to let it hang down by your side...
Brytenwalda is nice in that your shield is almost always held up high when you swing and such, but it's hard to get used to how different it is than how you hold a shield in native (it's held up, but off to your side).