OK, my 2 cents:
First, let me explain what I think a 1-second Combat Round (CR) is: Because it is is "so long" a CR is, by nature, an abstraction. This means that the actions themselves are somewhat abstract, at least to a degree. I don't say: "My fighter shuttles forward 3.5 feet, leading with my right, while extending by longsword in a thrust towards the orc's belly." I say; "I attack the orc with X OB, keeping Y OB for Defense (A much better term than Parry, I believe) against said orc." Then I roll my attack to see what happens. So, a level of abstract is inherent in the system.
Now, let me explain what I think a Weapon Skill is: When you train and use a weapon for long periods of time, you get familiar with it, meaning you get more and more comfortable in using said weapon. This means that not only are your movements faster and more accurate, but the way you incorporate it with your whole body movements get better and better. (Really, the only time when you want to be standing still when attacking is when you are using a missile weapon. Every other type of fighting style I have come across - armed and unarmed - emphasized movement.) So, movement is a big part of a weapon skill.
When you combine those two things (a 10-second combat round and movement as part of your weapon skill) you get an accurate assumption that while you are attacking (melee, of course) you are moving. So, some of your OB comes from positioning yourself, not just the "swing" of the weapon. This means that some of the OB can be used to defend against things that you cannot parry with your weapon. (I would put dagger vs. 2-handed sword when both parties are the same size, in this as well.)
To me, this means that, even against weirdly shaped and large foes, you can use some of your OB to defend against. If you are not going with that, then you should decrease the cost of Adrenal Defense and have it last so long as they pay the "maintenance" on it. (10% action, I believe.)