Very well, though allowing humans to build it would give a little economic boost to your kingdom. More people making more money buying more things and all that, ya know?
But it's not efficient. There's this problem of human error (we've had an AA turret collapse on this poor worker who was building it at the time because he built it upside down) and it takes much too long. Also, there's no physical labor involved when using machines and they're easier and cheaper than hiring people.
And people do build stuff themselves, such as houses, restaurants, stores, etc. They do things themselves and pay other people, but it's not our concern or duty to control and monitor everything that our people do.
We still have an economy and such. It's just that our actual money making and stuff comes from TT related actions while the RP part (citizens, cities, economy, etc) are separate. Example: we collect and sell Rodite for money (TT part). Our people sell and buy food at a restaurant (RP part).