That's why it's only at 2x in the deck. Everything else that functions off dishonor control (Insolence punished) just gets better with dishonored personalities.
In terms of defending, and saving provinces, that's generally not an issue I'm seeing. Between Two-Front War, and Doomed Intentions you have alot of straighten and move back in, and if you have a loaded up muhito, a ton of consecutive actions.
Against Honor, Irishii causes a boat load of trouble. Kurumi is great for getting dishonored people on the table as well. And having kaukatsu out has been a huge source of dishonor for me. I send him into battle, misdirect bows and other sorts of actions to him, and force them to dishonor an honorable personality. Further, if I pop off an assigning blame, they can either seppuku, which is fine by me, or they can let kaukatsu get off. In that situation, even if UB is a dead card, the threat of it made assigning blame that much better.
I know Saya is phenomenal, but this deck is pretty capable of getting dishonored people on the table.
Seriously though, it wins games.