What about:
- Challenger declares attack on hex and point value (max 2000)
- Defender is chosen and declares how many points will be used in defense (max 2000)
- Attacker can re-commit forces, up to 500 points more, but only by posting his list to the forum.
This gives the defender an advantage and allows people an easy way to intentionally lose a fight. If we want to give up a hex, someone can attack with 2000 points and we can just commit 250 points in defense ensuring that we don't lose any forces fighting for something we want to give up anyway.