From: McMinnville, OR
Basically, your situation is one of defense, so the only attacking you should be doing is in the counter-atk (to regain hexes neccesary to your line).
What you need is to set-up a line, move your artty to cover the expected enemy approaches, and dig in all the time! The best place(s) for the line would be the leading edge of hills and woods.
While there isn't much of a briefing, there IS google, LOL, which I reccomend to you.
"I have the brain of a Genius, and the heart of a Little Child. I keep them in a jar under my bed!"