Sabotage

Sabotages aren't hard to do even if you are playing by the no hit players rules. Hit a ruin outpost with no alliance. Use a feather if they are too far out for your agents to travel.

When you reach a certain level you can build a research tower. With enough research unlocked, you can research the speed and number of your agents. Increasing those will help out a lot.

You can also build more than one tavern and level them up.