#6 Unity of Command: "For every objective seek unity of command and unity of effort." I didn't include this because, with only ultra-rare exceptions, you control every unit in your army. That's pretty unified.
#8 Surprise: "Strike the enemy at a time or place or in a manner for which he is unprepared." Looking back, I could have included this. I think that, at the time, I was looking at things from an operational level and, since you can't really strike your enemy's army when he isn't expecting it (they'd still be in your buddy's shoebox or egg carton or whatever), then it doesn't really work for Warhammer. On a tactical level, you can still achieve surprise in many ways.
As a more in depth answer to Saint's question: Compare your 'awesomeness hitting the enemy's weakness' to Clausewitz's 'Center of Gravity.' There is a point that should be your main focus, around which your entire attack is based. Apply your awesomeness to that.
At the same time, the enemy is looking for your Center of Gravity, so you need to identify that and protect it. If both those things are in mind (attacking his CoG and protecting yours), then you don't have to worry about your enemy hitting your weakness. He might be able to hit your weak units, but shouldn't do substantial damage to your army as a whole.
As a sidenote, it's important to remember that the CoG is not neccesarily a unit. It can be a terrain piece. It can be an objective. In the War in the Pacific, the CoG was the supply lines. In the Civil War, it was Lee's army (all the previous generals thought it was this city or that city.) Etc...etc...
