Remember the Shogun Assassination Arc, when they wanted to use a copy of Shigeshige? (then it was too short, comic relief xD)
I think that they created a double of Shouyou, and that double would be Utsuro, or maybe vice versa: Shouyou is a created-double of Utsuro (but I would say that the created one is Utsuro, since his wound healed in a split second).
Anyway, Sorachi is one hell of a villain himself.