Optimization is about using as little as possible to acheive your goal. A Ford Pinto engine would never acheive the goals of an 18-wheeler. On the other hand, a huge V8 400 engine would be overkill for a Ford Pinto. It would work, and a beginner might use it because he knows it will work, but an expert would realize that the extra power is likely to destroy the wheels and waste gas, so he'd (or she) would prefer to use a smaller four banger to do the job.
I don't know why I'm posting this, I guess your metaphor intrigued me. :)