Story writers: What did they know, and when?

If I remember correctly, the clans were created right around January 1990 to address a game imbalance about 5 years after the game's first release. If I'm wrong about that, please let me know.

My question is, for the Federated Commonwealth, when and why did they create that alliance from a storytelling point of view? Did they know the clans were coming and wanted something to trigger that? Were they setting up for a massive 2 vs 3 war? Did they simply think it might be an interesting change-up? Did they always know it was going to end?

I'm just curious, and maybe nobody knows.