Terrorism in Dominions 3

[Executor]

You can patrol.
Units with patrol bonus patrol better.
While you can't demolish an enemy lab or temple, you can send a scout with a false idol that count as your own temple, I think, some nations have stealthy preachers to lower dominion inside the enemy territory.
A good way to shut down an enemy for is to cast unrest spells, or use spies to make upriseing, 5 should make over 100 unrest in a turn.
Once you plan to attack a fort, you can cast crumble to lower it's defense so you can storm the same tun for example.