Thanks, AlexAtticus.
The good news is that I've pretty much nailed down the secrets to getting high scores. The bad news is that there's one really dumb secret that completely dominates everything else, so really, the scoring system should be fixed -- see my post
"Military scoring is a bit out of whack". I find it odd that nobody has replied to it yet.
In the meantime, while we have made it to #1 thanks to strength in numbers, it looks to me like that's mainly because every other major empire is now so apathetic about recruiting.

I think we could do a bit more to enhance the community aspect of this empire.