...a couple of inches asymetrical and you could end up like the Ethiopian 767...
I said runway, not water, that's a different story. On a hard runway it will settle on the two engine pods as it would on wheels, as it was ably demonstrated. Rudder is more than sufficient to counteract any yaw from only one engine dragging momentarily.
The Ethiopian 767 cartwheeled because it was in a steep bank and out of control. There was a scuffle in the cockpit with the highjacker, it was not a controlled ditching.