That's entirely possible. Joe spends 3 years writing a program. Jim realizes that the program doesn't need to be written, and that if you frame the problem in a different way or use other resources available to you, you can come up with a better solution without writing any code.

Okay... more like, Joe can get done in a day what would take Jim a week.. or Joe can do more in a month, than Jim could do in a year. Perhaps the exponent is a bit off.. but more than cumulative output was implied.

A lot of this coming from being able to expect/plan for future enhancements/changes than the one-off output. My own personal reference with this comes from managing several projects with local and overseas teams with varying degrees of experience.

No.

Exponential effectiveness can only come from improving maintainability, readability and reducing code size. Fact that minimalistic approach also diminishes original development time is only a minor side effect. By the way, a true rockstar developer most of the time reduces code size and improves readability while adding features.

So when you see next time a commit, that adds features and reduces code size, - you know who you are dealing width.

Maybe not that extreme, but factor in things like future maintenance costs and lost productivity due to Joe's code being slow, unstable and buggy and you're probably not too far off.