For story's sake, I tried to define a sensible enemy, alliance, neutrality matrix:
DL friend: C, E Enemies: S, CI Neutral: MF
C friend: E, DL Enemies: CI, MF Neutral: S
E friend: DL, C Enemies: MF, S Neutral: CI
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MF friend: S, CI Enemies: E, C Neutral: DL
CI friend: MF, S Enemies: C, DL Neutral: E
S friend: CI, MF Enemies: DL, E Neutral: C
In the columns that have two entries, it would be a "primary" and "secondary" relationship. For example, DL's primary ally would be Chaos, and Elementals would be secondary. Primary enemy would be Sylvan, and secondary would be Celestial Imperium.
Notice that the primary enemies all line up head to head, and they're all dispersed equally. This took a little bit of thinking... some of these are obvious, which pushes the puzzle in certain directions. In terms of all out war, you can see a clear divide in the middle.
Random thought-- I'd also like to see this ideology integrated into future cards development... like when we have cards that are multi domain type.
And part of the beauty of this is that you can recycle! Let's say you come up with a great story idea... well... if it's a DL vs S campaign, then it's just a question of which side you're telling the story from, and how the story changes as one side succeeds over the other and visa-versa. *ahem, just like warcraft recycles story, for example*