From my previous readings, I understood that Soresu is the best defensive style with a weakness that practitioner has limited (counter)attack capability.While Shien uses the attack of your opponent to counterattack, but somewhat weakens your defense in the process (compared to Soresu).
Game mechanics tells a bit different story. While Soresu has improved version (which is more counterattack) of both parry / reflect, it has supreme version (which is pure enhanced defense) for parry only. It would make sense for me the other way around: more enhanced defense and less counterattack capability. You can get fired upon by lot more enemies than attacked in melee, and you can hold your ground much better with Shien, as you run out of strain real quick without supreme reflect. At the same time, Soresu is lot better at counterattack than Shien. Should not it be the opposite?
I have not received my copy of Keeping the Peace yet, but does it change anything regarding this?