I think you have a point Brian_ in that when the AI clans start too small with lots of rebels the player can give them hell either by turtling to tiping point and then exploding or by blitzing from the start - either way it can work, although the turtle and explode is less risky.

I prefer the classic "Sengoku" campaign for this reason, i find it much better for the gameplay that the AI clans have substantial territories and rebels are few, but that's just me.

For what is worth, the "dates" campaigns are more historically accurate in terms of what each clan occupies.