No way to expand

[Vladimir]

I'm playing a Saga campaign and I'm trying to be a good imperial clan. I've conquered 2 shogunate clans in my vicinity and other imperial clans took out the others. I have to go several turns east by navy just to get to the first shogunate clan, something that will be pratically suicide for my army.

Have any of you experienced the same thing? What did you do?

Stab them in the back, quietly. I had a vassal I didn't want turning on me after Realm Divide so I caused a rebellion while they had their army in a fleet. They were on the way to attack a mutual enemy but I didn't need them hanging around. In my first game my allies are so incompetent that I didn't have to engage them directly.