I tell my students that the purpose of Engineering is not to build something stronger. It is to build something as weak as possible without breaking. Any baron can conscript a bunch of peasants and build a castle with walls 10 meters thick. But some will go bankrupt trying. Or, get an engineer to figure out how to build a wall 50 cm thick that can withstand trebuchet attacks.
If you're not minimizing something, you're not engineering.