At the end of the day nothing about the number of commits was used in your thoughtful analysis, it was only the contents of the commits which you attribute any value.
Yes and no. Certainly I know lots of great developers who prefer to commit work frequently and incrementally, others who do slower bigger changes. But I don't think I know any engineers who can create a substantial amount of software with only infrequently and tiny changes.
I encourage you to look at the code produced by whoever you think is the top engineer in your team or company (and I'm talking only about the engineers whose job is still primarily hands-on coding, versus advising/mentoring/architecting etc). Now look at the code by that one person who you know isn't pulling their weight and who you think isn't getting much done. I'll wager that your top engineer is pumping out a ton of strong code, and the other one is a trickle.
