(About the title)
I like the word "startegy"!
It could mean the strategies for the first few rounds. e.g.:
- hiking taxes up to 200% and patrolling with your initial army
- the pros and cons of appointing a prophet immediately vs waiting until you can hire a super priest (e.g. the Neifel Jarl or Arch-Thug) or even waiting for a specific hero to turn up
- hiring mercenaries for quick initial expansion vs building up your own national troops
- what spells to research first, or what items to forge in the first few rounds
- try to get a foothold in the sea (or on land for Atlantis/R'lyeh) early or not?
These are a lot less dependent on what other nations are in your game, so could be put into a reasonably small document.