You could probably pretty easily separate Fallout 2's story into two games.
One focusing on the Tribal -> Enclave storyline
One focusing on the rebuilding of California and the Wasteland Politics of NCR-Vault City-Reno and the survivors of The Unity.

I'm of the opinion that the Enclave really could have used an extra game of buildup before actually appearing, especially now when they've been permanently slotted into the greater antagonist role.