Broct gave me the idea to make decorations worth building. So i came up with these examples.
Come with more suggestions or examples.

Horseman Statue gives increased transport speed for gens, and some kind of bonus for our cavs.
Soldier Statue gives morale for our soldiers making them hit harder.
Small Merchant statue makes scouts/explorers give a bit more of the resource the find and increase the possebilety for finding adventures. Or making faster at there work
Angel Monument gives our soldiers increased health.
Angel Gate increases the numbers our gen. can command.