I think the metric for scoring should just be the sum of all "NW losses your attack/spy caused to the target you just attacked/spied" which I'll just call "NW Damage". Meaning, it also counts landgrabs as NW losses that you caused.

This forces players to choose carefully:
Should I grab to grow (and minimally increase my score)?
Or should I mass BR (the attack that causes the most NW loss)?
But if I BR too much, at some point, GSes become better scoring as the turret and building count gets too low.
And likewise, I need to prevent myself from being crippled so I can continue to cripple others, so I can't GS away all my troops and leave none behind.
Or maybe I could mass Demo then BR. Or mass Bomb Jets/etc.

This completely takes away the focus from killing countries at all, because there is little incentive to kill a country, you don't get much "NW damage" score out of it, and focuses on strategic crippling.

If this becomes a solo server mode, then high "NW damage" scoring countries would become targeted for crippling. Might be interesting.